Master Yi's early game is tough, so try and look for easier lanes to gank, you can get a lot of damage out with your E+Ignite, you can dodge and use your Q to chase. And W auto attack reset is your strongest weapon in the early game, nobody expects that much damage randomly. Basically when one of your autos are done just W and start another one without waiting for your attack speed.

Try and always go for the scuttle crab fight, as you can almost always beat the enemy jungler with your ignite. You can also use your smite on the scuttle to gain extra health, meanwhile your enemy is still struggling with ignite grevious wounds if he tries to do the same.

You can't gank as much as the other charaters in the early game so try and do your best to powerfarm through it and help out people if you're in the area. If you get 1-2 free kills in the early game, you snowball like hell.

The reason why I don't like berserker's greaves as boots option is because you don't really need more attack speed as Yi, you need to survive those nasty skillshots that the enemy will almost always save for you.

I don't recommend playing Yi above Platinum because it'll be hard as hell. Suit yourself though. The reason I prefer on-hit more than the draktharr build is because it's more consistent. Your job as Master Yi is to melt down tanks and take out carries. You are stacking on True Damage with attack speed, you're not stacking on Armor Penetration. This essentially means that you will kill tanks as well as you kill squishies. If you wanna kill squishies go play Kha'zix or Rengar or something. With Master Yi, you will be able to kill squishies, but your main job is to stop the overfed Nasus pushing toplane all the time, if you get what I mean.