I love the scrappy look, but I still must have a theme or plan of some kind. In my case, it is generally 1930's reproductions. I've done Dresden Plate and am now working on Friendship squares. Next will be the new one from Quilt in a Day. I keep my background constant (generally Kona snow) and use as many repros as I can get my hands on.
All that being said, I've seen some scrappy quilts on here that appear to be an explosion of the scrap bin and they look very pretty, too. I just don't have the nerve to try that style yet.