I can't help, though it isn't so much the quilts I have a problem finishing, it is some of the sewing projects. The quilts usually have somewhere to go. THe biggest thing is finding your own rythm that works for you the best.
If I am working on more than one thing, and it happens, I have a parts bin stand with a lot of the bins on it, I put all the pieces for the square in one with the name etc on a sticky. I keep a binder where I plan my quilts in it that I just go there for directions if I get lost how it goes together.