Astronaut Teemo required

Enemies Disintegrate: intoxicated with cosmic matter collected from Blackholes around the galactic neighborhood. Teemo thought it would be amusing to upgrade his laser cannon with an new phase-locked quantum beam generator. Unleashing classified technology from YASA (Yordle Aeronautics and Space Administration), champions and turrets alike shall melt before your fuzzy feet ;D muuhahaha

» Building Toxic Shot first is an important strategy toward wiping out minion to (1)) feed on gold and (2)) push your lane forward. It's important to learn how to lead with your basic attack which activates the Toxic Shot passive-poison. Mastering this shot-sequence will result in more shots-per-burst and thus more damage dealt. Here's how: Lead with basic attack, then immediately hit Q and land the Blind then in the same second, right-click to re-land another basic attack (which occurs about 1/4-second after the Blind shot - worth the slight wait.) A triple shot, and with this AD+MP, quite effective.

» Blind is picked second (note sequence below), such that you should have a few shots on your opponent, then once you quickly reach lvl.2, you can grab blind and hit the enemy champion [combined with Ignite], either killing them or forcing them back to base.

» Move Quick is third to provide some escapability, whereas we wont have enhanced movement speed (through Zeal) for a few lvls, this is needed in basic for for last resorts and then not built until much later in order to promote more damage through the other two skills first. You'll notice we first max Toxic Shot, then we max Blind and last finish off Move Quick.

Rune-strategy is uniquely built to remold Teemo into a stronger beast, of Pure Galactic Destruction xD

Built around decreasing Teemo's squishiness through armor seals, then adding armor and magic penetration marks, progressive magic resistance seals in addition to slight cool-down-reduction and topped off with triple magic penetration quint's.

The special feature of this build is its use of the Insight runes. In case you didn't know, these work exceedingly well with [Astronaut] Teemo's toxic shot and satellite dishes to deal as much magic [poison] damage as possible. This is a key feature of this champion that should not be neglected. This build is unique because Teemo uses the AntiNeutrinos collected near the event horizon of Blackholes in the poison of this build. Blind, toxic shot and noxious trap are all enhanced by the destabilizing properties of these subatomic-[death]-particles.

Focused to give Teemo Maximum AD pack-a-punch g00dn3ss xD

All 30 points on Offensive AD:

You'll find these items both build quickly and do effective damage, which should help you dominate your lane or team-fight.

Forget boots, the Zeal is your boots, just as effective (speed-wise) and you get AS + Critical Chance. Later when it upgrades to Phantom Dancer, those benefits increase.

Depending on how you're doing and how your game is progressing, you could skip the B. F. Sword and immediately get The Black Cleaver. Later on, the same could be said for the Infinity Edge. It really depends on how you are doing - if your team is fed and you are pushing in easily, you may want to skip the B. F. Swords and go straight to their upgrades, however if your game is an equal battle going back-and-forth then you should use the upgrade-path. However, a wise Champion must always weigh the time it takes to go back and then return to battle vs. assisting teammates, feeding or pushing.

Once you get the Atma, your Damage will be over 600 per shot, and your shots will be pretty fast ;D
Then adding the Bloodthirster is just ridiculous: the quantum-particle beam doesn't even touch them and your enemies vaporize out of sheer horror!

Ignite for offense, Teleport for defense ~ this is a team game after all ;)

Many people choose to save their ignite for the very last moment to ensure an opponent's death. May I also introduce a progressive draining strategy such that if you use your Ignite often, it will play games with the enemy's mind and may cause them to go back more often. The idea is to maximize feeding and increase gold input and XP. I do agree that Ignites are useful for final-kills, but I would suggest doing both, and keep in mind the sooner you use the spell the sooner it will return and allow for more damage, so use it often and at those wise perfect moments.

Teleport is so essential for saving turrets and getting up to their base to kill-feed in the last throws of the game. Also keep in mind that you can Teleport to a Noxious Trap: hide a couple in useful yet obscure places (where they wont be hit, say a corner of their jungle or the back wall of their base) and you can quickly surprise or jump back into action.

Great Solo or as Teammate: Poison Does Not Discriminate!
I prefer to run this Teemo at mid, but do not get set in that way alone. This has to be based upon your opponent at mid. If you are out-ranged, take serious pause. Champions such as Karthus, Graves and Heimerdinger can be an issue if you are not prepared with an anti-range counter strategy or your team does not have a jungling-ganker. If you are out-ranged, and/or if you are dieing 0/2, consider switching mid with a teammate. Otherwise, you should dominate mid, especially against squishier champ's like other [non-spacey] Yordles, Ashe, an non built Ahri, etc.
If you do swap mid or play bottom or top lane with a 'mate, then you are on support and blind mode. Stay back and barrage your enemies with annoying toxins. Focus the front-most champion and provide blinding-support for your teammate (especially great when they are a melee, fighter or tank.) Be smart, play back and safe, yet very aggressive!


Avoiding Damage: The Swift Scout!
Your speed is your friend, so save your Quick Move for attacks and escapes. (Also useful for rushing back into your lane, but those are rechargeable distances.) When you activate Quick Move to attack, hit them with a few shots then run back around the minions to get out of damage-range. Do not run straight lines often - enemies will pick up on that. Attack forward and immediately run sideways or in an arc to avoid counter-attacks. Remember that most moves and especially Ult's have a slight warning, so if you see Lux's laser pointer or hear Kog's belch (as e.x.), move your fuzzy butt to the side ASAP! I'll say it again, Always Keep Moving (and you will stay alive more often.)


Noxious Traps: Use Offensively And Defensively!
» With an OFFENSIVE strategy...
Creeps: you'll run through the approaching creeps and set the satellite dish after the first group of three (3) creeps, (thus into the second ranged group) immediately turning around to shoot the first group of three then following-up with the second group to cash in on all of their gold.
Champions: Set the traps at places commonly traveled. For instance, watch where your champion runs when you set a path - look at what edges they run near, what part of the bushes you cross, etcetera - place your satellite dish(s) in those places [where the enemy has the best statistical chance of hitting them when running through the jungle.] Another good place is just around the corner from the wall of your base, where Champions will lurk (just out of turret range) but within special-attack range (think Ashe or Kog'.)
» With a DEFENSIVE strategy...
Creeps: Place the trap directly in-front and right-next to the turret. This will stop melee minions when they approach to bash your turret. (Incidentally it also helps the same with champ's.) I like to then place one at the next minion-meeting-point ahead of the turret to counter the next wave.
Champions: As mentioned above, a Noxious Trap right in-front of a turret will always annoy an up-close fighter/tank.) A key feature of the Noxious Trap is that it is a [relatively] free mini-vision ward. You need to first build your lane's defense, then quickly start warding the hot spots in the jungle and around the map. Ramps, Dragon, Baron, Jungle Bosses, etc, put a trap down to know where your enemy is when what they are up to - it will save you later. In the same regard, ward the bushes immediately near yourself and your opponents, which will help them not get ganked.


Ganking: The Element of Surprise and Disintegration.
Once you reach the Phantom Dancer with this item-build, you should be capable of effective ganking by dealing tons of damage. (Gauge your skill, at this point, or when you get the following B.F. Sword.)

Creeps == Gold:
Feed well: Teemo should stay back behind the creep-line and fellow teammates as a general rule, but I've also specially built this Teemo for my own aggressive play-style. Stay back but also play quite-aggressively in order to feed on gold/experience. Hit the minions from your max range, or close to them, and as soon as the enemy is in range, Blind and stay targeted for 1/2-second to get the second regular shot, then run back and re-target the closest minion. As suggested above, use your satellite dishes to quickly melt through entire creep waves and rush up a lane.

Jungling: Mid To Late Game Buffing.
This build can kill a jungle creatures, but is mostly built to gather quick gold from lane-creeps. Later in the game, once you have destroyed your lane's turret (this will give you a time-buff essentially), then run back into your jungle and get a Buff or take out some smaller creatures for gold. Later, just grab the Red And/Or Blue Buff(s) and then really punish your opponents.

Winning is impossible without teamwork. You must work with your team and foster a productive team mentality. (You are "Capt'n Teemo" by-the-way.)

Remember that negativity DESTROYS MORAL. Do not talk badly about your team (or the other team, just not cool.) BE A LEADER! If someone is being talked down to or disrespected, put a stop to it. Consider that if it's your own team, that person my subconsciously give-up or worse, and thus you lose. And if it's the opponents team, well stand up for that person and be a good example by defending their feelings.