An update on my DIY Tufting Technique. I realized that I could completely bypass the whole threading-a-button-through-the-headboard-holes thing by just carefully screwing a wide-headed screw down in through the hole I had made in the foam.
Don't quite need the ottoman but this might work for the bench I'm looking to do. How to Build an Upholstered Storage Ottoman. This gives you the measurements of every piece of wood and fabric along with a list of what tools you will need.