I'm at the stage of life where I can do them on the floor but not without getting up and down many times to stretch my back and knees. So I did a couple lap quilts on a queen bed with firm mattress, layering and then reaching under the 3 layers to pin them, starting in the middle and working out. Luckily it seems to work fine. Occasionally I would give the quilt a couple stretches or tugs to be sure the bottom layer was not wrinkled. Sure was easier on my back. It was a bed in guest room so I could leave it for a day or 2. Recently still put a larger quilt on the floor.