Here's a few Hometalk ideas: https://www.hometalk.com/search/posts?filter=bench%20headboard.
Here's another tutorial you might like: https://www.youtube.com/watch?v=-uR5bOge-Qw
The headboard is the back and the foot board is cut in two to make the side pieces. You need to build a frame inside to hold them together. Look at the tutorials online. There are a lot of them.
Louise, here is a bench made from a bed frame, both the head board and the foot. Hope this helps. I think it is beautiful!