Depends how customizable you want to make your template, I guess! I tried out a few people’s designs…
This one inserts really easily and holds well, but the pegs are a little thinner and I don’t know how much they lose in strength,
This is a very nice friction-edge one, which worked really well. (My preference for the angled hook type instead of the friction edge type is mainly based on the desire to easily and frequently reposition it.)
The one in my design was derived from @markevans36301’s linked above — I lengthened the top peg to make it fit my thicker pegboard, and made it a hair thinner for easier insert, thus:
