First kill blue. Then if you are purple gank mid, or gank bot if u are blue. Go in with Q and put box behind enemies. A box will help if enemies want to escape. Later do what you think you should do :) GOOD LUCK

I prefer smite with flash but you can also take smite with ignite, heal or ghost.

If you complete all the build you can sell Youmuu's Ghostblade and buy Infinity Edge, Bloodthrister or if you are a piece of paper buy something more tanky.

If you don't have quientessence for armor penetriation you can aslo use quientessence for attack damage or armor.