Finishing both sides of a cabinet door at the same time poses problems. You could stand it up or perhaps hang it from something, but it really is a process done best with the door laid flat. It once occurred to me that I could make “legs” for my doors to hold them up off the worksurface during finishing. I fasten a pair of small scrap legs into the hinge mortise areas with short screws and drive a longer screw through the hole that will receive the doorknob screw. This gives me a triangulated base. I finish the side with the legs and screw facing up, then flip the door over and finish the other side. When I’m through, the holes in the mortises will be hidden by the hinges.