I love the Hobbs fusible batting, especially for smaller projects which will fit on my pressing table.
For larger quilts, I get out the 8' square makeshift basting table, which puts the work surface about waist high on me. I layer the backing, batt and top like usual, just in case I get some spots where the back side of the fusible melts, it'll be fusing to the backing instead of to the plywood sheets.
After I've fused the top, I flip it over and smooth it out and fuse the backing. Then I usually put it right side up again and bring the backing around to the front and pin it all around to the edge of the quilt top. It keeps me from sewing too close to the edge of the quilt and it protects the layers from coming unstuck around the outside.
I wish they made the fusible in the giant 120" square size that the regular King batt comes in - for the King quilts, I usually end up cutting strips off of a second batt to do the borders.
I try to always stock up on these when they're on sale at Connecting Threads.