I cut the strips from 2" up to 3" depending on the look I want.
Each type of batting and the particular loft, fills the binding differently, so auditioning binding onto these scraps may be helpful.
Make mini quilt sandwiches. Cut two fabrics and batting 4" wide X 6" long.
Cut a few scrap bindings 2 1/4" - 2 1/2" X 6" and sew them onto the mini sandwiches. You can then play with the seam allowance as well as the width of your binding. Fold the binding over, and make changes according to how you want the finished binding to look.
Write in pen on these samples, the type/loft of batting, width of binding strip, seam allowance, etc... or staple them to a sheet of paper and write the info on that. Then you can refer back to them on future projects :D:D:D