Stick to it? There are people who stick to a plan? I'm confused by your question. Do you mean that you only work on one thing at a time? Is that possible?
But seriously, to answer your question, I probably have 20 quilts in various states of completion at the moment, from waiting to be quilted, to needing basting, to partially pieced or waiting to be pieced tops. I do whatever catches my eye or interest at any given moment. When I start to feel like there's too much going on, I take those projects that are closest to completion and do those first, to knock things off my list. I make a lot of gifts, but avoid taking commissions or committing myself to gifts for particular holidays. That way, even though I'm making a birthday present, I'm not committed to which birthday a person gets the gift.