I open up with doran's blade to deal more damage at the beginning of the game and deal more damage to the enemy champs. It makes it easyer for your team to pick up kills.

Berserker Greaves is the best choice of boots because you shoot faster. The faster you shoot, the more damage Toxic arrows deal. Boots of Mobility also works.

Malady is a very good item to buy with Teemo. It makes you shoot fast and gives you additional damage on your q, e and your r attacks.

Nashor's Tooth does pretty much the same as Malady, but it also gives you mana regeneration and 25% cooldown reduction.

Bloodthirster gives you 60 additional attack damage and 20% lifesteal. This is a huge advantage in 1v1 and teamfight's. If you are low and it's no other champs on your lane you dont have to recall, but you can stay and shoot on minions to get a lot of life back.

Frozen Mallet is pretty useful. It gives you 700 HP and 20 additional attack damage. This make you less squishy and you will mostely sure not be the one who gets targeted first in teamfights. It also gives you a passive that slows the target by 30% for 2,5 seconds(40% for melee champs).

At the end of the game, I sells Doran's Blade and buy Guardian angel. Guardian angel gives you a ''second chance''. When you dies you just lies in the ground in a few seconds before you respawn with hal of your life. This ability has a cooldown on 5 minutes.

Flash works extremely well as a escape spell and as a chase spell to catch up with enemy champs.

It works well if a champ is low on life and are trying to escape or in a teamfight to deal more damage.