I'll give you some of my ability to start new ones if you give me some of your finish what you start :) I have 11 going right now and am determined not to start anymore as I have at least one in every stage.
My suggestion, is there a pattern you want to do? if not, find one and start cutting and just do it, no matter how much that other one is calling you. Maybe start with a small wall hanging or baby quilt. Or do something different than you're doing or have been doing. Go through your stash or go buy a fabric that you wouldn't normally use and try something different. It helps expand the mind. Maybe too much for me...