One of the most important parts to launching high altitude balloons is obviously making sure the balloon and parachute stays attached to the payload. To accomplish this, we use a bowline knot. The bowline knot is often referred to as the "king of knots" in boating because it is strong, as well as easy to tie and untie.
When making a bowline knot, there is a very easy mneumonic to remember how to do it. The top end of the string is a tree and the bottom end, a rabbit.
1. The rabbit pops up through the hole
2. Circles the tree
3. Goes back down through it's hole.