This build is about giving Teemo as much attack speed and damage as possible .

First Blood

Most times i play with Teemo i get the fb . I always buy Doran's Blade and Health Potion and then rush to the mid . I get there before my opponet cause of my raised speed and then i wait there in stealth mode . When the enemy comes and pass me i start attacking him (camouflage's atk speed helps a lot) and i use Ignite , when he starts retreating (they always do) i use the Exhaust to slow and kill him . Even if he manage to get behind the turret my poison will kill him . When the enemy revives and come back i am already lvl 3 and own him ^^ .

Gameplay

Solo : When i solo mid i try to trap my enemy . I put my shrooms all around the mid line where the enemy will try to escape and some more near Baron and Dragon so i will know if any other enemy wil try to come mid . Then i keep distance from enemy (especially if my mid-opponet is mage , cause of Teemo **** M Resist) and try to lure them near my shrooms . If the enemy is mage i try to kill him with shrooms , if he is fighter then Blinding Dart rules ^^ . I can even solo tanks like Morde if my Exhaust and Ignite are ready .

Team Work : In late game when we fight all vs all the best way to play is to act like a bait . While the rest team hides (f.e in grass ) i lure the enemies to them and put shrooms to the way after me so when we reach my rest team they are already slowed and poisoned . When the fight starts i stay behind my team and keep poisoning all the the other enemies all the time .

*I always have a shroom ready for use just in case i have low life and get attacked or i get ganged which i put behind me so i can escape .
*When fighting minions poison all of them first in order to have the control at your line .

Items

After Doran's Blade next thing i buy is Emblem of Valour , a really useful item cause even if u have low life u can stay in stealth mode and regain hp while your minions give you xp . Then i buy Berserker's Greaves so i can hunt or escape my enemies and i complete my Stark's Fervor . I think that it is the best lifesteal item as it gives high lifesteal , atk speed (which is essential for Teemo ) and armor penetration . Next thing is Last Whisper cause its armor penetration is very important in my game . With these items Teemo can take many kills in early game . The rest things Phantom Dancer , The Black Cleaver and Infinity Edge are all items focused on damage , atk speed and crit strike with which Teemo rules at lvl 18 .

*Another thing you could use instead of Last Whisper is Sword Of The Divine , cause it deals 100 extra magic damage every 4 hits and with Teemo's atk speed that means 100 extra dmg every 2 sec . I just prefer the Last Whisper cause it has permanent Armor Penetration .
*In case the enemy team has many mages i replace one of the things above with Wit's End which gives Atk Speed , Magic Resist , removes Mana and gives extra Dmg . Something that is really useful if you manage to remove all of your mage enemy's mana , then he will be just +1 kill .

I prefer 24 points in offense cause it makes a very offensive and killer Teemo . I want the 3 points in Perseverence cause Teemo runs too often out of Mana and the 3 points in Good Hands just cause i am really bored when i am dead :P .

Most builds i have seen here are like 9x same Mark , 9x same Seal etc . I really dont like that and i have used more different runes cause i try to ballance all the stats that Teemo needs in fight .

Pros : The biggest advantage of Teemo is his poison and the shrooms which will give him many kills even when Teemo is dead , i have scored a double kill when i was dead :P . Also his speed that allows him to hunt or escape from enemies .

Cons : The only disadvantage of Teemo is his low Def and M Resist that make him the favourite target of the enemy team .

I hope that you liked my build . Please vote and comment.
Have fun !!!