I think the most important lesson mentioned here is to take breaks. This is for any repetitive job. When quilting, I have my small iron set up next to my machine so I can pivot and press, but I take my chain piecing to my stand up iron station to do. This makes me get up, move and stand while pressing. I can work a lot longer by doing this. I also set a timer, so that every few hours I do a physical thing. This can be as simple as take out the trash, walk out to get the mail or walk to the corner and back. On the times when I feel I am under a deadline and don't do this, my body rebels the next day. That couple minutes relief really lets me work many, many more hours. This is advice for us at a certain (?!?) age, you youngins probably don't have these problems yet!