I've made these for a window seat. I just purchased 4" thick foam from JoAnn's with a coupon of course. I just opened the fabric up, centered the foam in the middle of it, trim to size and fold it over like wrapping a present. I hand stitched it closed and them using a long craft needle I hand tied it. For the holidays I just "wrap" it with fabric, instead of hand stitching it closed I safety pin it, when Christmas is over I just unpin it and store the fabric for next year.