I used to double-tie my shoe laces to keep them from coming undone. After about 40 years, I figured out I was using a granny knot when I stumbled upon a web site describing the Ian Knot - a very fast way to tie a square knot with your shoe laces. It takes a few minutes to figure out how to do it, but Ian's method is the only way I tie shoe laces now.

Abax