Gall is the assassin part of Cho'Gall. He is a little tricky when it comes to using his moves because you might aim to shoot a skillshot by Cho might move away and make you miss. This is why they required either experience or teamwork.

Tier 1

The Eye of Kilrogg comes in handy for a few reasons. The first reason is that it acts as a ward so you can see a gank coming. Place it in the outer bushes depending on which lane you are in so it can detected enemy heroes coming to clean you up. When you see them, signal to Cho so he can use Surging Fist to get out of their. Though depending on how many champions are coming, you can take them on. The second reason the Eye of Kilrogg comes in handy is to have vision to be able to land skillshots behind enemy towers.

Tier 2

Bomb's Away is another strategical talent that will come in handy. This will combo well with Cho's talent Rollback. With these two talents together, landing Rune Bomb will be much easier since you have more range to hit enemy heroes from far and on the way back, you can make it curve. Remember that if the original throw for Rune Bomb is a little off, wait for the Rollback talent to take place so you can land it and let out the massive DMG that comes from that move.

Tier 3

More coming soon... Also be sure to check out my Cho guide!:
http://www.heroesfire.com/hots/guide/cho-the-walking-tank-7609