Original headboard - in great shape, I just wanted to modernize it a bit
I cut foam (I think one inch thick...) to fill in the inside of the already framed headboard and glued it to the wood
Then I covered the entire headboard with quilting batting and used a staple gun to staple it in the back, then repeated the same step with fabric, making sure it was really tight.
Then I individually nailed every single nailhead for the trim by hand. It also comes as attached rows of nailheads that would have been faster, but in my opinion it didn't look quite as nice. For each nailhead, I first took a real nail and hammered it in a bit to "pave the way" for the nailhead trim and I found the trim went in much easier. It took about 250 nails, a rubber mallet, and two nights of Olympics watching, to finish the trim but I love it!