I use a double bed all the time. It's tricky because you have to go around and around to keep it flat, so I generally only do up to twin or throw sized quilts that way. It is a little hard on the back, too, so I need to take breaks. If it's a bigger quilt and I want to quilt it myself, I take it to our town's historical building which has some folding tables that can be set up to use. Your public library may also have a few. It actually takes less time to do that than it takes using the bed. I'm now thinking of getting a folding table of my own and storing it under a bed. I've been taking bigger quilts to a long arm quilting friend lately, though. She does a great job!