In starting your game, you need critical strikes for farming minions. Starting with the Brawlers Gloves and some health potions so you don't need to get back to your base to farm more..

Starting your game with an early first blood will help you to build this Early Game Guide or (EGG/Early GG :D). Or to make First blood you need this items. Start with the Avarice Blade and next the Zeal. Then nest the Bilgewater Cutlass for lifesteal so you don't need to buy some health potions..

Items with Very Big Life Steal, Attack Speed, Critical Strikes and an Item that can slow Enemies is very helpful to be a Master Carry! Bloodthirster, Infinity Edge and Yoummu's Ghostblade is the best partners for AD Carries.

Emergency Game Build. One of the most important build. If you are in the point of losing and the enemies are already inside your base, you need this. Armor and Health. Just in-case..

Critical Strikes, Lifesteals, Attack Speed and Attack Damage are the items you need for Master Yi. You can do Triple kill, Quadra kill or Penta kill with only 100- health remaining with this Items.. Example, if you have 200 AD and the critical strike is 1000 then you have 200% lifesteal and have 100 health, you can get 2000 or higher health restored, then having high attack speed.. Imagine! Awesome isn't it?!?!