I quilt and sew, so I have quite a few projects going at one time.
I like to piece when I go to a quilt retreat. So I cut out 2 or 4 projects to take with me. I usually spend about half a day on each one. I usually stick with those projects until I get all of the blocks pieced. Then I have to be in the mood to put the blocks together. I may have several hanging on my design wall waiting for the borders to be put on. Then I wait until I am in a real creative mood to put them on my long arm and quilt them. In between I will be working on a table runner... maybe matching placemants or napkins... or some other smaller projects, also. Some days you want to start and finish something.I think I would wonder what was wrong with someone that only worked on one project at a time!