I have one of the craft tables that the sides fold down. I have basted more than 1 king quilt on this table and numerous queens down to baby quilts. Here's my process. Lay backing wrong side up with about equal amounts of fabric on the long sides and equal amounts on the short sides. Secure with binder/bulldog clips. I have 1 large box of these. I use 3-4 on the long sides of the table and 2-3 on the short sides. Place batting on table, again with equal amounts hanging over. Starting in the middle of the long side, remove clamp from backing and clamp the 2 layers together. Do the same thing with the remaining clamps on that side. Move to the other long side and repeat process. Do the same for the 2 short ends of the table. Lay quilt top over everything centering over other 2 layers and repeat the unclamping/reclamping. There are times that I've had to reposition to make sure there is enough batting/backing on all sides of the quilt. Once the center section is clamped into place, pin or thread baste as you normally would. Now with everything basted, shift the whole sandwich to one side or the other. Make sure you have a basted section to work from when starting to reclamp the first edge. Go about smoothing and clamping as before. It's alot of going round and round the table for a large quilt but, IMO, sure beats doing it on the floor! No need for boards at all.