Welcome!

This guide is at its basic form right now, this is what I wish to achieve, and I’ll cross out as I go:
Put up the basics
Create the in-depth
-Add in supports (only official ones) and adc's (same)
Try different items, see their effectiveness with Twitch
Try jungle Twitch, if I think it's viable I'll add it in
Make it look nice
Harass someone into doing some art
-Art for chapters
-Something really cool for introduction
Continue expanding, adding in new strategy’s and ideas (never intend to finish this one)

If you wish to make a recommendation about something in my guide, that I’m missing or can be done better, then just post a comment. I’ll give credit to everyone who does, even though I’m sure you don’t care.

Pros: - Underestimated - Your E is forgotten a lot - His Q allows for easy ganks - W a good slow, proc's E fast - support reliance minimal - passive finishes off out of reach enemies - hard to gank - Q can trick champions when escaping

Cons: - He only has two damage abilities, be careful in straight up duels with other adc’s - His Q is short, be careful - His E has a long cool down for such an ability, make sure to follow up on your attacks if it’s on cool down - He is a very easy champion to burst down, positioning is key in a twitch player

Early game, you want to proc your E as fast as possible, but you can't limit yourself to that and neglect actual damage. That's why I've put a lot of attack speed runes in here, but haven't limited myself to them. Besides that, less experienced players would have a problem last hitting without some attack attack damage in there.

When I get the long sword, these are alternate runes I add on:
9x glyphs of attack speed
3 x quint of attack speed

I get butcher instead of frenzy because twitch doesn't have much reliance on critical strikes, nor is he short on attack speed, and you don't have critical strikes early game for it to be effective. With butcher, I can add a couple more attack damage to my strikes to; once again, make last hitting easier early game since I took attack speed runes. I also grab improved recall as my last point, because I will be using twitch's Q as an aggressive play, and that time reduction will greatly help me at times where I get caught out, and it has an added advantage in-lane since I tend to recall after a push in order to get an edge on my opponent. You can also recall while activating your Q, so that's also why I get it.

If you don’t want to waste a point on a better recall, just add one into cooldown reduction, or even frenzy if you feel the need.

The only other spell I’d recommend would be exhaust, but Twitch needs to be able to escape fast if he gets caught by accident so I’d prefer it if you put cleanse on. Ignite is useless, it’s concept is to finish off enemies that get away with that little bit of health, yet twitch’s passive already has that effect. I find it a totally unnecessary spell for twitch.

All items will be referred up into my build at the top, explanations and all. It’s easier material access if you are unsure about my choices, and it also means you can find all alternate item builds I put up through a glance. What I will put here is an in-depth look at every item and it’s benefit, instead of the overall benefit you can refer to up at my build.

Also, let me say this. NEVER get doran's blade. Whether you’re losing or winning, it puts you behind. With twitch, you don't need doran's blade to add that extra damage, his E far exceeds and requirement for such things and since you are getting a bloodthirster so early, the healing effect of it is also useless. Make no mistake; you'll regret buying a doran's blade.

Defensive Items:

Never get any defensive item besides the guardian angel or the mercurial scimitar, not for any reason. Health, armor, magic resist, it’s all useless on an adc. Your job is to be able to deal as much damage as possible on your team, which means you are going to get focused HARD. Adding some more health on top will not save you from an imminent death after being caught, you only have one choice.

Don’t be caught. Getting a guardian angel is viable though, since its benefit is a revive instead. Yet only in certain circumstances would I even recommend that. If you didn’t get cleanse though, the scimitar is the perfect choice for you. Get it, since you won’t always be perfect and if you get caught you need to get out.

I had a look at wit’s end, and I deem it not viable. While the magic damage is intriguing for me, it’s stats, overall, don’t provide enough damage to be worth it. Remember, you need as much damage as possible (I am including attack speed and life steal etc. in this).

Offensive Items:

Executionor’s calling: this is not viable, I’ve had a look. Investing in the item will put you behind others, in the end not making it worth it. I’ve heard mention that it’s amazing against heavy life-stealing enemies like fiora, but I do not believe so.

Fiora, for example, will still life steal way too much for you to handle an up close fight with her. If you ever get into fights with such enemy’s, run, that is all you can do. Only attack from a position away from them, usually with your ulti to maintain the distance.

I had to mention this since I’m sure many of you have been led astray by it, now onto the items I use.

The bloodthirster: It’s amazing lifesteal is something incredibly useful early-game, when you are in the lane. Not only will this item provide you with much better sustain then an adc who doesn’t get it, by farming your minions you can gain up to another 30 attack damage and 6% life steal. This means you can out-lane any adc who picks another item first.

Phantom Dancer: I get this straight after because I obviously want to proc twitch’s E as fast as possible, the phantom dancer provides me with the best stats to do just that. Not only that, it’s movement speed buff greatly helps when I proc my E to position next to enemies, and it’s passive of obstacle avoidance allows me to chase escaping enemies faster, getting caught on minions chunks a lot more of your time then you think.

Infinity Edge: One of the best damage items in the game, it provides me with 70 attack damage and a huge chance at landing a critical hit, with the damage of the critical itself being increased. It’s a must have on all adc’s, but since it’s damage relies more on the luck side I don’t get it so early.

The Black Cleaver: This item provides nice damage, adds a little health for you, and reduces your cool downs. While this is useful, it truly shines through its passive, which provides armor pen and armor reduction for every hit up to 25% armor reduction. It shreds anyone who builds tanky, and added with twitch’s ult can take out multiple enemies quite quickly.

Situational Items:

Runaan’s Hurricane: It’s explained up in my build, in the notes, but the essence of this item is to help me fight my battles by myself, aka when I have a team that is bad.

Guardian Angel: Again, explained in my build, but the essence is to help me win a game where I have a good team, aka a team which can back me up while I revive.

Most people decide twitch’s choice of attacks should be E Q W.
While I agree with everything up to E, the rest is totally wrong, in my opinion. I believe both the Q and the W are simultaneous spells. By that, I mean that they work best by using them together, and as such, they work best when they both have points in it. The Q is designed to get close to enemies unaware, so as to launch a surprise attack. The W is designed to slow escaping enemies, so you can pile on as much damage as possible. Putting these two together allows you to launch a surprise attack and keep them there through your slows, ensuring your victory. Alternating between the Q and W allows you to increase the time you have to reach a person, but also the amount of speed the slow takes. Maxing the W takes almost half their speed off them, a significant advantage over your foe.
This is why I alternate Q and W.
Of course, your E is always the number 1 priority. Always get it over anything else.

If facing an aggressive enemy:

If your enemy is acting overly aggressive, and making you fight them a lot, I prefer to stave off getting my Q and putting in another point in my E to increase my damage. I won’t be going anywhere anytime soon, so I might as well give myself more damage to fight.

If facing a passive enemy:

If the enemy is overly passive, then get your Q before getting your W, so you can use Q and push up to launch a surprise attack on them. Make sure your support knows what you’re doing though.

Start Game:

Once you have your items, instantly head for the tri-bush down at bot and camp there until either the minions have reached the middle, or the jungler requests help. Now just farm, farm, farm, farm. Harass when you see opportunities, but never be over-aggressive in-lane. Kills are not worth deaths, contrary to popular belief.
If you’ve become competent at twitch, and believe in your skills, I’d suggest that once you hit the level three mark to start going semi-aggressive. Don’t over-extend, but you can put a lot of harass on the enemy which they can’t do anything about. Once you’ve either killed them, or pushed them back and hit level 4, go gank mid. Do this by going through the lane bushes, not going around otherwise you’ll be discovered by the turret (unless they’re right at their tower. If your lane is pushed, go back and attack/farm/push, then head back to base. Buy accordingly.

Early Game:

Now head back to lane, if you see the enemy still in-lane, and you believe you can take them, activate your Q and then head in for a surprise attack. The enemy’s usual response is to run, since they’ve been caught off-guard, giving you victory. Push the lane once again, and go for a gank. It’s recommended you take the long way this time, through the enemy jungle, since they’ll probably be warding out of fear.
Head back, push lane/harass etc. and go to base. Do this until the laning phase is over, which signifies mid game. If it’s 15 mins before that happens, push and take out their tower since you don’t really need to be in-lane anymore.

Mid Game:

Now this is when you really start roaming, doesn’t matter if your team is doing so too. If you’ve been dominating, change to aggressive. It really helps if your support is warding a lot, since you can use your Q to surprise unwary enemies. Remember though, never be too aggressive without flash or cleanse since if you’re caught, you’re dead.
Now, your team should be grouping at this point, it’s time for you guys to push. Never rely on your team though, unless you know they’re skilled. Always watch for enemies, and stay behind them if some get close. You should be able to push all the way to inhibitor, then back off and grab dragon if it’s available, base, regroup and retry. If your team gets caught out, don’t fight a losing battle and back off so that you can protect the towers.
Also remember that your stealth is really useful to go into the jungle, and to escape it. Check their red and blue buffs while hunting for enemies.

Late Game:

This is around the time that one team or the other has gotten an inhibitor, if it’s you then good job, if it’s not then there’s only one way to win. Hold off until you get all your items. THIS is the ONLY way to win a losing battle, besides being lucky and scoring an ace. If you’re winning, don’t go straight for the nexus. Be careful with the enemy, one mess up could cost you the game.

The Fighting:

Your the adc, and contrary to popular belief, your job is NOT to deal as much damage in the shortest time possible. No, it is to stay alive, no matter what.
Even if this means flashing and cleansing, only to rejoin the fight. You have to make sure you are never in a position to be easily cc'd or burst. If I get caught, I usually flash away and activate my ult, staying in the fight without danger.

As twitch, it's best to not be in the fight to begin with, but rather have your team initiate and you join right afterwards in stealth mode. They are not prepared for you, since they never saw you, giving you precious few seconds to pile on the damage without respite, then back off and activate your ultimate.

Additional Strategy's:

Your Q is also useful to catch up to any stragglers, since the movement buff and they don't know your there. If you see your team losing badly though, I recommend backing off once they come for you and just heading towards your tower. There's no point in staying on the off-chance you'll beat them, rather retreat to your tower to hold them off until the next fight. The adc has the easiest job in holding off enemies.

when enemies are at baron, wait until baron is a third of the health, then activate your ult and attack baron. You should be able to get your stacks up to 6, which you can then use expunge to deal the last damage to Baron, hopefully they don't use smite. Also, with the bounce effect, you can damage the enemies too allowing you to pick up a kill sometimes. Same thing with dragon as well, whether your attacking it or the enemy is use expunge to finish it off. Never take chances.

Anything about twitch I'm interested in, I'll post here. Whether it's a new strategy, an idea I just thought of or a complaint about his bad skins. You'll see it here

If you have something to say, but fear backlash, send me a pm here. I promise you I will always be polite no matter what, and take whatever you say into consideration. Also, unless you state otherwise, I will never mention the source.

14/02/2013: Fixed up a few minor grammar mistakes.
13/02/2013: Don't consider this my proper guide yet, eventually I will be satisfied. Updated a lot of information in the items, runes, masteries and spells. Few minor changes in grammar etc.

Any ones posted will be put up (or sent to me), might eventually put up a video myself if I feel the need.

Eventually there will be people here :D