So far Andrea has been able to reuse old window coverings for the beds. In one case she was able to use one of the old insulated window coverings which didn't require being filled with any additional stuffing. In that case the process was as simple as folding the fabric in half, and sewing the edges together. In situations requiring additional stuff she leaves one edge unsealed, and then fills with whatever stuffing she has, before sewing up the final edge. Andrea has no trouble coming up with stuffing, because she has been saving scraps for years for this very purpose. She has saved pieces of fabric, fleece, batting, and even old clothes that can be used in this way.
When we started having to contain Jack, so he could recover from his injury, we realized that rain could blow into his crate, and ultimately collect underneath his bed. To prevent the water from soaking through, Andrea wanted to make a bed with a water-resistant bottom. She was able to accomplish this by using a piece of old vinyl shower curtain as the bottom. The most interesting thing is that the shower curtain was clear, which means that when the bed gets flipped over the transparent bottom allows a view of the stuffing, which is a random assortment of colors, shapes, and materials.
We've been using the new bed in Jack's crate for a couple of weeks. Occasionally we'll switch it out with another one, so it can dry out if it has gotten wet. Since the water isn't able to soak through to the stuffing, however, it doesn't take long at all for it to air dry.