I don't think i should type out 10 pages like some guide when it is pretty simple, After a certain point in the game your become an auto attack machine and you should stop casting Piltover Peacemaker because you will lose DPS because of it. Yes there are times that you should use it such as killing some one through a wall or to hit more than 1 target but in a 1v1 fight or even in team fights once the build is about 1/2 way done you should just auto attack and use your ulti and throw some traps around to be a good team player.

Start Dagger and what ever potion you want then go for Berserker's Greaves, after that get another dagger and if you want to or feel like you need it you can get a Vampiric Scepter befor the B.F. Sword or even just some where in the middle after Berserker's Greaves other than that you can get Infinity Edge befor Starks or even befor you finish Phantom Dancer if your doing well enough.

Build 2 is for more DPS if you feel like you dont need the life steal as early. I go with more of the second build most of the time but a mix some where in the middle will work as well since they are basically the same items.

Try to take middle lane if you can, with your range just try to rack up as much money as you can with last hits. Try to use your passive (Headshot) to harass the enemy champ. A useful trick is that you can use 90 Caliber Net as basically a flash so when the enemy thinks there about to get away you can aim it backwards to get that last hit or tower dive just to blast your self back to safty. I'll update this later after i have some screen shots of a few games.

Oh yeah, get red buff since you don't have a CC and why get an item when you can just get a buff thats better anyways?
Well thats all for now GLHF and remember its never to tacky to yell "BOOM HEADSHOT!" when you nail an Ace in the Hole.