All of you would be interested in the book I started reading last night. It is Heirloom Machine Quilting by Harriet Hargrave. I checked on Amazon to see if it would let me look at the page on work space but no such luck. Just for the benefit of my good friends here on the board, I will summarize this section.
She first recommends a cabinet with you machine set in. If you don't have that, the next best thing would be an extension table. It needs to have a slick surface for the fabric to glide over. Avoid wood. It should extend 4" from the front of the machine, 24"-36" to the left and 18"-24" behind.
Make sure your chair has a large enough seat so it does not cut off circulation to your legs. Your chair should be high enough so that you can lean over your work slightly, relax your elbows on the table edge and take the stress off your shoulders and back.
This may all seem like a lot of bother, but reaching up with your arms to place and move the quilt under the needle puts a lot of stress on your back and between your shoulder blades. Also, you have much better vision and control when you look down on your work. Lift your chair high enough so that you can see down on the presser foot and fabric. You need to see the needle going in and out of the hole in the presser foot. Check that the glare from the machine's light bulb does not also cause vision problems.
Finally, place your chair far enough back so that you can lean forward. Set your elbows or forearms on the edge of the table and rest your upper body weight on them. Relax your arms and hands. Place your hands on the quilt as though you are playing the piano, LIft the wrists, keeping the fingertips on the surface, so the fingers are ready to walk wherever you need them. By positioning your hands in this manner, the stress to your wrists is minimal. If your hands or wrists begin to ache, readjust the height you are sitting and the position of your hands. Your hands should fall forward naturally from the wrists in a relaxed state. If you do experience any discomfort, you may want to wear the therapeutic gloves made to support your wrists.
Okay, me again! Quilting gloves or machiners really do help to get a grip on your quilt. When I took a machine quilting class, the teacher recommended putting an empty fabric bolt under the back of your machine to raise the back enough to get a better view of your work area. You probably would not do this if you have your machine set into your sewing table.
I hope this helps!