One of my machines, a Bernina, used to give me a back and shoulder ache when I used it for over an hour. I seem to be a bit taller than the average or maybe just awkward. Anyway, i was wandering around Walmart looking for answers because I was determined to be comfortable sewing on the Bernina. I looked in lots of departments and considered assorted answers. I wanted to do this one myself. And I wanted it now.
And then I got into the kitchen area and there was the answer - a rectangular, aluminum baking pan just like the one I'd been using for cakes and coffee cakes, etc. If I turned it upside down it was just the right size height to help the Bernina problem. And what's more it was inexpensive, sturdy, stable, etc., etc. When I considered it, the pluses for trying my idea out just continued on and on.
It came home and has made the Bernina the crown of the sewing room. And no more backaches. Decide on your bottom line and then think outside the box. You may find "cake pans" in your future.
Have a good one. PS: all the counter tops, etc. in our house are about 2" higher than usual.
Pat