I know what you mean. Sometimes I pile pillows on my chair or use an adjustable t.v. tray. Walmart had or has black or grey t.v. trays that are wide enough to handle a machine. I use one when I am traveling or sewing at our church for charity quilting. It does make a difference on your shoulders if you are having to reach up. A real no-no in ergonomics.
Some people cut out and stack blocks of insulation and then top it off with vinyl for the fabric to slide smoothly on the surface. This way you can inexpensively customize your work surface surrounding your machine.