I am one of the one-at-a-time quilters. I honestly don't know why I am that way. I have a stash, so I don't wait to buy fabric as I am about to make a quilt, but I only work on one quilt at a time. Once I get to the hand sewing part of binding, that is when I think of my next quilt.
I tried making a list of quilts I wanted to make one time, as I really thought my one-at-a-timeness was rather wrong. Everyone else has lots of quilts going on. I thought knowing which quilt I wanted to do next was sort of a compromise. Well, that list just made me rush through the quilts just to "get them done." It was no fun at all. I felt stressed to "finish the list."
I have been quilting for 6 years, and I have made 115 quilts so far. I only started quilting after I retired, but I was a serious seamstress until then. I did have a rule though, my own self-imposed rule, that if I bought fabric, I had to make it into a dress (skirt, slacks....etc.) by the next payday or I shouldn't have bought the fabric. (teachers are only paid once a month) Money was short, and that was my thought process. I think that maybe I changed that rule to the one-quilt-at-a-time rule when I retired and started quilting.
At any rate, we are all different and I am quite happy making only one quilt at a time. I have no UFO's, no kits waiting, nothing in the "ready box," just a wonderful stash of fabrics I like. One at a time makes me happy. I also have no hints on how to help someone become a one-at-a-time quilter. Sounds like some sort of behavior modification thing, and I know nothing about that. I am a serious creature of habit.
Just do what makes you happy.
That's what I do.
Dina