I don't tie my shoes in any of these ways.
I was home sick one day and I watched some dumb talk show. In the show, a European gentleman told the story of walking down the street with his American friend only to have the friend stop and retie his shoes several times. Why? Because, it seems, we Americans tend to tie our shoes with a half hitch which gets looser and looser as we walk (especially with certain types of laces). The Europeans, he said, tie using a square knot that gets tighter as they walk.
I spent the rest of my teaching career showing students this easy way to tie shoes -- after training myself for over two months so it became a habit. It's hard to explain, but easy to show.
1. start with the half knot
2. put one lace over the other across the shoe
3. make two loops, the upper lace loop goes under and the lower lace loop goes over
4. pull tight as usual
What you will have is a square knot. It is removed in the same way as the half hitch tie which is to pull the ends so the knot comes undone. This knot will not come undone until you want it to. No need to double knot the laces anymore for children.
I took very few sick days. This was one day the I actually learned something.