The key to a fast and successful farm is the ability to semi micro. Obviously you need to start off by using the 2nd skill on creeps (creeps below lvl 5). The key part is when the creep is within 2 shots of dying, then you need to make sure to move your EIDOLON's to the next camp and tank up the last 2-3hits by the creep.

Advance Tip : - If you have decent micro skills you may micro your EIDOLON's (in the jungle) while farming the lane