Success!! I made the padded headboard I've been thinking about since I moved into this apartment. It's in version 1 at this point, but it is great to have it up there as I'd hoped!
My dad was kind enough to put together the frame out of 2"x3" boards and a big beadboard piece, and I bought a few yards of "Nu-Foam" at JoAnn with my 50% off coupon. I glued the foam on and then covered it with a tan fake leather that was $3/yard on clearance. I put seams on it rather than pulling and stapling, to give it hard edges. My plan is to make changeable covers in fun fabrics that fit the 60" by 48" padded portion and slide them over the vinyl. That way, I can wash the changeable fabrics and keep moisture out of the padding. Perfect for reading in bed! I bolted the legs to my cheap metal Hollywood bed frame with two bolts on each side, through holes drilled in the wood. Nothing fancy, but it works.
The total cost was... about $20 for hardware/wood/bolts and about $15 for the two yards of fabric and three yards of NuFoam. Plus the staples, and other fabric pieces I will make into slipcovers. All in all, a success!