I taught preschool for years. Every once in a while, I had a child ASK to learn to tie shoes, so I would sit down with this child and it would draw a crowd of kids who wanted to learn too.
I always started with one step at a time. This way you do not overwelm them with the entire task. When you break it down to a little one, it's a LOT to remember to do. I only taught one step each week and let the child practice it each time we put on the shoes. (Summer is a good time because for some reason shoes keep coming off and on all day.)
Step 1: "Criss-Cross, Criss jumps in the hole; then pull" (this is the base knot).
Step 2: "Make a loop, not too big."
Step 3: "Tie my thumb to the tree."
Step 4: "Now pull it free."
This last step will stump them until they realize which hole to pull it through, but once they do. WOW!
It's great to accomplish a new task on your own.