Well after playing Twitch for such a long time and finding some very good guides for pure lvl 30's i thought it was about time that i put my touch on it. I have also included hinters and pointers for people that are lower in level. These are depicted by the text in Green

I have also added three different builds for the three main player styles i use. 2 Offensive and 1 Defensive.

DISLAIMER

This is my build and it works great for me. One of the biggest things with twitch is finding your build, your style and what works for you. I have tried other builds and i get little success this one however gives me great success.... so try it, customize it and see if it works for you. If not try another guide and mix and match, you will find what suits your play style!

PROS:

• Great at ganging
• INVIS INVIS INVIS In low level games this isn't countered.. YAY
• Handy at escaping
• Can penta kill very easily
• Great harrasss early game
• Lots of fun
• Has a decent slow move
• Ranged, always a bonus
• Can still kill a champion with a little luck even after your dead
• Can wipe out waves of creaps very easily, stunting a push

CONS:

• Very squishy More so without your Quintessence of Health
• Very slow movement
• Is a high priority Target
• Vulnerable to Oricles/Wards
• In higher level games requires teamwork
• CANT TANK AT ALL

As stated above the standard Rune build for Twitch is:

• Greater Mark of Desolation This will really help in the starting phase of the game. Nearly all champions will be treated as if they are 0 armor meaning you get to do more damage!
• Greater Seal of Evasion As stated in the cons you are Very Squishy, the dodge percent chance from this will allow you to have a Tra La La affect as you remain alive and they die... AGAIN
• Greater Glyph of Scaling Magic Resist This is to stop those pesky mages and try to correct the lower magic armor you have especially late game.
• Greater Quintessence of Health Your HP, you need it early game to be able to kill one on one, its as simple as that!

Getting lower runes cost quite a bit (early levels) and waiste quite a lot of IP. Remember that once you hit lvl 20 you can get third tier runes. You are going to need about 15000 IP to buy them all so save if you can. If you are forced to buy runes, skip lvl 1 and only get lvl 2 runes

Masteries are a little bit of a personal choice.

I prefer the attack speed from Alacrity instead of the Cooldown Reduction from Sorcery and as such am unable to get the magic penetration from Archaic Knowledge .
Personally i belieave that you need to hit more as you are a DPS and it doesnt matter about the magic pen for Expunge

I use 1 point on Burning Embers for early game bonus, boost Expunge a little bit and can be the difference of winning early game battles. This can be changed out very easily if you prefer more CDR from Archaic Knowledge or the speed bonus of Nimbleness

only put 1 point on Resistance as this is made up by your Greater Glyph of Scaling Magic Resist


The other key thing i can say is even from low levels. ALWAYS get 3 levels in Hardiness without it you will fall very very fast! that little bit of armor can make a huge difference to your start game!

My choice for summoner skills are quite simple:

• Flash Once skilled with the use of this skill you will be surprised at what you can do. I shall write a new secton just for this skill to explain some of the uses and how to use it correctly with twitch.
  
• Ignite This is generally linked to my D as i find it easier to press. Its a great damage dealer especially when stacked with the Damage over Time of Deadly Venom. It will get you early kills and with the mastery attacked makes your expunge do that little bit more early game.
  

Before level 7 you wont have access to Ignite. It sucks but its not that big of a problem. Get Heal

Some alternative Spells are:
Teleport This used to be my get back into action move. I try to never leave battle until i have the gold i need early game. Once i recall i buy/heal and Teleport back in. Less time out of battle means more lvls on expunge and Ambush

Cleanse A great skill for twitch if you are destined to face a lot of Crowd Control.. (stuns ect). Although if Twitch is played right, they wont have time to target you and you shouldnt need this.

Ghost This isn't really that handy with twitch as you will primarily get boots of movement to get around and if you cant Ambush and get invis you generally wont escape even with ghost. Chasing isnt an issue either with Venom Cask

Exhaust Obvious advantage is 1v1 against a DPS. this lowers their damage by 70% which means you can actually take a few hits.

Heal Using this skill you will get a LOT of criticism.... that said, twitch is all about finding what works for you and trust me i have seen heal work.. You are super sqwishy and this boost even in late game can mean the difference between life and death IF USED CORRECTLY!

Not really useful Spells:
Smite You are not a jungler

Rally Your not a tank

Fortify You shouldnt be visible or hugging towers

Clarity If you need this you are playing twitch wrong

Clairvoyance Theres much better things to get

Revive Why on earth are you letting yourself get caught?

Flash is one of the most versatile and commonly used summoner spells in all of LOL.

With twitch you really do use it a lot like most champions, flash over walls to escape or just to get a little distance when they try and jump you.. Remember how i keep saying you are super sqwishy, this can and generally will allow you to escape. The thing is that is not the only use for flash and i shall give you a few hinters i have found work.

FLASH WORKS WHILE INVIS.
yes u heard me correctly... and your asking why on earth would you want to flash invis... well here is why...
If someone has ward or oracle, hit Ambush.. as soon as you invis, flash and you are now generally out of range of their ward,oracle or very close to. A few weaves and you are safe. Just remember dont flash until you are actually invis or it wont work!
Another good time is if you have a nukers who are watching you invis as you enter a bush, duke em, ambush, run in to bush, flash and all of a sudden they have waisted all their nukes and have no idea where you are... after all twitch is all about the element of surprise!

OFFENSIVE USE
Flash is an offensive skill and should only be used that way to guarentee a kill. if its only 50/50 dont do it! if you are going to die... DONT DO IT. A lot of times enemies will be just outside your range and although you may be able to hit them with spray and pray people like caitlyn, ezreal or katerina will use their skills to gain distance and thus escape. A quick flash in and a few more hits will make all the difference when you go to slow them with Venom Cask and will allow you then to get your 6 stacks to expunge and get the kill.

SKILLS
EXPUNGE

Deadly Venom PASSIVE This adds a poison stack for every hit that you land on a target. With a maximum of six stacks, this skill is DOT (Damage over Time) causing 2.5/5/7.5 Damage Per Second per Stack or/and is manipulated by your other skills. Stacks last for 8 seconds from last hit.

Ambush This is your invis skill. Once active it takes two seconds of not recieving damage before you turn invisbile. Twitch becomes stealthed for 10 / 20 / 30 / 40 / 50 seconds. If Twitch attacks a unit while Stealthed, he gains 30 / 45 / 60 / 80 / 100% attack speed for up to 10 seconds, depending on how long he was stealthed before attacking.

Venom Cask As suggested its to debilitate (slow) all the nearby enemy champions' move speed by 30%, plus 6% per Deadly Venom they have. 2.5 / 3.25 / 4 / 4.75 / 5.25 second duration. It has a deceptively long range!

expunge Twitch uses the stacks of poison already on a player and sucks them away, Deals 30 / 60 / 90 / 120 / 150 (+100% of ability power) magic damage to each nearby poisoned enemy, plus 20 / 30 / 40 / 50 / 60 additional damage per stack of Deadly Venom applied to them.

Spray and Pray Twitches ultimate. Twitch gains 15 / 25 / 35 attack damage and his attacks become long range line missiles for 12 seconds, dealing 100% damage and poisoning all enemies hit (Yes effects hit every target). During this duration, a maximum of 5 / 6 / 7 missiles can be fired. Downside is that it shoots in a straight line so if the enemy is running on an angle this can and generally will miss them once active!

ORDER/WHY
Theres really two ways to start as twitch, the Scout or The Harasser, i always play the Harrasser.

If you prefer to scount change the following skill combo's to start with Ambush and use it to scout the bushes before the first wave. Getting expunge next and follow normal sequance.

I start though with Expunge for the chance of pre lvl 2 kills. Yes they happen, More so if you have a stunner on your side.

You will always want to max your Expunge first as it does a substantual amount of damage and is your last hitting move, ensuring you get the kills you rightly deserve.

The next one to max is obviously Ambush. This is your backdooring/ganging/towering/escaping/tralala skill. Its fun and when used right will make the other team call MIA (MISSING IN ACTION) all the time. Forcing them to waiste cash on wards etc.

ALWAYS when it becomes available put a point on Spray and Pray. its the tool that makes quadra's possible.

Finally you only need 1 point on Venom Cask early game. putting more points on it is a waiste.

In a gang/fight your skills sequence should be:
Ambush-> Spray and Pray-> Venom Cask-> expunge

Obviously all of the items in my builds are build on DPS/CRIT and Attack speed. When i get more time i will explain them in detail but until then just remember aim for max Attack speed and a little healing as you will need it. Starks is always good for this. Damage and attack speed is your madreds and black cleaver. Crit and attackspeed is your phantom dancer and well infinity edge is perfect synnergy.

Farming with Twitch is actually very very easy although it goes in stages.

Early game, All you do is last hit. During this phase of the game you should be more focused on harassing then pushing and only last hit creeps. You will need to be able to last hit at least 50% of the creeps to do well here. If your not killing then last hitting 90-100% is the way to go (especially if you are soloing).

I cant stress this enough, EVERY CHANCE YOU GET, hit an enemy chamption at least once then fall back. Your passive ( Deadly Venom) will do the rest. IF a champion has ran out of health pots and is 1/2 health or under OR your team mate is up for it, fall back as if you are going to run back to tower to recall. Once out of their vision, Ambush then run back towards them. Indicate your target using G, run behind them and target them so u pop out of Ambush getting the attack speed bonus. IMMEDIATELY use Ignite and Bilgewater Cutlass if u have it. Generally by this stage they will run but if they dont dont stress you always have a trump card. WAIT FOR THE MAXIMUM STACKS of Deadly Venom that you can allow (preferably 6, but if you are in fear of dying pop it early) and pop Expunge. People will be pissed and want to try it again as they will generally hurt you quite a lot but you will nearly always win.

A good strategy for positioning though if you can is place yourself just outside of the bushes behind your enemy. This will allow for a last minute run. Turn on Ambush and run straight into the bush. By the time they enter you will generally be Invisible!

By Mid game you would already have Zeal and a B.F.Sword, enough said, mow down those creeps and start your push, Remember to ambush before going at the tower, the added attack speed with your B.F. Sword will make the tower drop in no time.

After LVL 6, if you see a large wave in a lane and you can get there, Ambush, run to the side of the creeps so that they are in a single line in front of you, attack the closest then pop Spray and Prey. This will make the entire wave go bye bye in just a few seconds and score you some nice cash.

Your job as twitch now is very simple, SCOUT, GANG, GANG, GANG, SCOUT, BACKDOOR, GANG.

There is very little room in there for solo heroics and twitch is really not specifically built for that.... Yes you can backdoor a few lone sqwishiees and why not, but you are really there to help the team wipe them out.

Your job is to scout the area (with Ambush) when a battle is about to begin so you know numbers, locats and items (Dont forget to check for Vision Ward/ Oracle's Elixir). Then you wait.

Only after the battle has started and they have chosen a target for you to strike. Take the extra 1/2 a second to position yourself to strike the majority of them with Spray and Pray, then let loose. Hit them up to 6 times (or when they start to run) and pop Venom Cask. Hit them the rest of the 6 and Expunge.

Dont forget to time it so you get a few kills as well.

Oh and late game, if done right this will get you Tripple kills to Quadra Kills.

If you have a madred's and somoene to tank Baron will fall very quickly, but thats really not what this part of the guide is about.

I really just wanted to remind you that you are a SCOUT and a very very CHEAP player......
As long as the other team doesnt have an oricle... and if you and your team have been doing your job that shouldnt be a problem. Once the opposition disapears, check Baron.

If they are there (generally because they have taken down some of your team or kicking their buts) dont run but stay invis in the back of the baron alcove.

Indicate to your team that they are there so they can start an ambush on them, thats their job, yours is to focus on baron. Wait till the enemy has it very low, target baron, hit, Spray and Pray, and steal the bloody thing.

Ive done this multiple times and with the damage they have recieved from Baron, the fact that your entire team now has the Aura, Them in a small confined space with Spray and Pray, very few if any of their team will survive, changing the course of battle

Low level games rarely use these items, but it is good to read through as, when you get to level 30, They are used continually!!!

These will be the bane of your existance....

If you cant invis you are useles...

OR ARE YOU.....

Pay close attention to which wards the enemy team is placing and where they are placing them. If its a sight ward, meh laugh at them and continue what you are doing, just remember they have a larger sight for when you are visible.

Vision Ward Now this is a different story! They will always be able to see you if you are in range, unless you are in a bush (ward is not in bush) or you are outside the range of the ward. These are annoying but not impossible to beat. As soon as they drop the ward look at the time. Remember the spot as it is now a bad area for you for the next 2 minutes. Make sure youre team is on the lookout for them as well and lets you know where and when they are placed. More often then not they are placed in the centre of an isle, this isnt an issue as their are generally bushes on either side, perfect for an ambush... and they have a range. You can walk around the range through the jungle and backdoor them still.
ALTERNATE COUNTER:
If you saw where the ward was placed and have your ultime ( Spray and Pray) ready then line up a mob so that it will go through them and hit the location of the invisble ward. If done correctly you will destroy the ward without even needing to see it. This will force the opposition to change their strategy!

Oracle's Elixir is the bane of your existance... a moving vision ward.... DAMN...
as soon as anyone has one on them they are your teams prime traget. If there is no way of you taking them down, ask someone to come for the gang. You will need to either be sneaky and avoid them or kill them its that simple. If that cant happen swap lanes with someone and make another one of their team go for this little beauty.

Remember:
Your enemy will be spending money on Vision Ward and Oracle's Elixir... this is a good thing. Its more money they arent spending on damage which will help your team in short term as well as the long run!

Vision Ward and sight ward can be countered with an Oracle's Elixir of your own. Although if you can get around doing this i would. As soon as you get an Oracle's Elixir then they will follow suit!