I make sure to always have at least two going at once. Three is best, because that gives me more freedom to step away from them. More than that is usually too many for me and they begin to pile up into UFOs. They seem to me to be kind of like wine or cheese...sometimes they just have to have time to mature to the next step before they "speak" to me again. Sometimes, I've had them wait for a year or more, and then I eventually finish them, or realize I'm never going to finish them and figure they were there to teach. I have one that has been sitting around for about three years, but I don't consider it a UFO. It's just not ready to move forward, and I like what I've done on it too much to not ever finish it. It's just I can't figure how to do the rest yet. It's a wall art quilt with a city scape at sunset. My mind's eye can finish the top half of the quilt, but not the bottom half yet. So anyway, I think the answer is whatever works for the individual quilter...for me the ideal is 3. Cheers, BJ