This thread offers interesting insight into how we work.
I have multiple projects going all the time. My passion is art quilts, which take a lot of thought and attention. They can be on the design wall for months waiting for inspiration and thought. Currently there are 3 up, occupying my 2 design walls. If I stall, put up a layer of felt and start another quilt on top. The room is fairly well organized. Don't touch anything, you'll mess up my system, that no one but myself can understand.
Then my mind needs a break, so I do something fairly easy. Usually this is because I'm trying to downsize my stash. Charity quilts fit this group, 1/day=4-7 yds off the shelves.
Another reason for multiple projects: the machine I'm using. When going to outside quilt groups, I take my always-packed tote: 11# machine (very small harp), cords, ironing station, tools, fan, seat cushion, extension cords & power strip. This requires a project that needs less concentration so I can talk with friends. Also, can only piece on this machine. Then quilting the projects is done at home on the heavier machine with large harp & easy FMQ. The quilting is where I usually stall out. Currently the long arm is stacked with fabric. Also, due to plumbing work, some painting needs to be done before it can be put back in order.
Now, this all leads to a flaw, procrastination. What can I say?