Pay Per Click (PPC) Strategy!

I have recently been spending a lot of time trying to improve my PPC campaigns. Although my campaigns (that are running) are profitable i believe that i am missing out on a lot of earnings potential specifically due to my relative inexperience.This is a particular area of concern as most of my traffic is obtained using PPC, although i am also concentrating on SEO for my main keywords. I have read much on creating the perfect campaign, however their is always that feeling that i have missed some...