I agree, I have used the tilt table, and have the petal also at a similar angle, (and height)for both feet I have found that this helps. Now I have a big acrylic bed for my sewing machine and don't think the tilt will work. More than anything it makes you sit back, instead of leaning over your work.
Taking frequent breaks are really important. I found that when you start making mistakes, stop, take a break. Relax, and when you come back it will be better. I have also heard--so I sure can't prove it--that if you are trying to learn a new skill do it right before you go to bed. I guess there is some kind of imprinting that goes on, while you sleep.