Best exercise to tone stomach area sides etc?

I have lost over 2 stone the past few months and have went from quite fat to quite slim but i'm not toned at all really, i want to remain slim but be toned so i don't look flabby or anything. I want muslce but i don't want to look like a huge body builder, i eat very poor though and i'm extremely picky but one thing i will eat is chicken dippers which is probably the highest protein low fat food i eat, could i get toned by getting my main source of protein from them? and what are the quickest exercise to achieve this body?