Step-1 Many objects could be used inside the knot preferably round or square but I chose to use a marble. The marble is light weight and you can get it in different sizes.
Step-2 I recommand using some sort of pointy object I chose my nail punch. Once the knot is finished the pointy object will aid you when pulling the cord to tighten the knot around the marble.
Step-6 Insert the marble in the center of the knot.
Step-12 I made a diamond knot and snake stitch but any type of finishing could be applied.
The first few attempts could go wrong - this knot needs a LOT of patience so take your time and especially the final tightening part, do it slowly and you will get a cool Monkey's fist.
In the second guide I am just showing another method of holding the cord between the fingers. It is convenient way for small marbles.
I was just thinking that not everyone finds it easy making the monkey fist knot between 2 fingers so I made this DIY aid I call it the "easy monkey's fist". All that is needed is to wrap the cord correctly in the monkey fist knot then take it off and tighten it.
It's made from scrap timber (L-shape screwed together) and 4" nails. I drilled nail sized diameter holes so the nails could be removed / pulled out easily. The small gap on the base is for holding the start cord and 3 screws (optional) to fix it to a solid base.
I tried it my self a few times and it only took me a few minutes to make a perfect monkey's fist.
Just remember, do it slowly dont pull to hard on the first few tightenings.
I found today some 8mm cord and made a giant monkey fist using golf ball and tennis ball as core.