With the rise of the Internet I began searching about knots and found animated gif's showing how to tie them. The instructions for the Monkey's Fist were tough to follow. Eventually a friend of mine figured it out and then showed me. It is actually an easy knot. It takes about one minute to tie and 10 minutes to tighten.
I always tie the 4 loop version. I tied a five once but I didn't particularly like the way it looked.
Here is an example of my signature keychain. It is a four loop fist with a hang man's noose. The fist hangs out of your pocket. I think it is stylish and you don't have to dig around for your keys.
When you tie a fist, it works best to have fairly rigid rope. The size of the ball bearing makes a big difference. If the bearing or rock is too small the knot collapses a bit and doesn't have a good shape. If the bearing is too large it will show.
Monkey's fists have several purposes. It's traditionally used for heaving lines. You have it tied to one of the large ropes used to dock ships. Since they are too big to toss to shore, the monkey's fist is thrown and then you heave up the larger rope up.