I read Don Asslett's book, "Is There Life After Housework?" and he says having several things going at the same time is a good way to get things done. You work one one thing until you need a break from it, then go to the next, and the next... Then when you come back to the first project, you're fresh and ready to do it again.
I decided (about 20 years ago) to catalog all of my started projects. I had 75 and decided I was sick and had to change my ways. LOL!
Now, all I get done are samples for the store. I think I have 4, and just brought another one home today, so 5.