First a warning. This has the potential to burn you. Please ask any questions you need to before starting this project as you undertake this project at your own risk.
Now that you have accepted your fate, you will want to set up the double boiler with the wax and start melting it on medium high (you may need to set it higher depending on how fast you want the wax to melt) on the oven cook top (unless you have something else that can melt the wax) and then turn it down low enough where the wax doesn't start to solidify.
This is the time you will want to apply the lotion and then place your hand in the bowl or bucket of ice water for 10 to 15 seconds.
You will then dip your hand once quickly in the wax in the position you want it to be molded and immediately return it to the ice water to cool.
Continue alternating from the wax to the ice water 10 or so times depending on how thick you want the mold.