1. The only knot is a simple over and under-through, forming a pentagonal shape 2, 3. Then the loose end of the belt is fed through the underside 4. A back fold and twist are made after tightening 5, 6. And the end is then fed through the topside 7, 8. Tidy up and loop the belt round the back if it is too long. Feeding the right and pulling the loose left end will tighten the fit.

NOTE: You will want to stitch the pentagon shape, so it doesn't come undone. A needle and thread are all you need. Take care not to obstruct the slots needed for pass-through. Use thinner kids' belts for best effect.