I personally don't like Yi the way most people play him,You know a beast of attack speed damage and critical but which gets completely destroyed by a thornmail or high armoured champs..So this is how I like yi...

I start with abecause this combined with the AP runes makes harassing opponents withso easy...It will also greatly boost youreffect...When my opponents are low but not in range I love doing the---->---->combo in order to kill them :)...And dont worry about farming creeps...will do it for you..