Put shea butter into a glass jar that has a good lid such as a pint-sized canning jar.
Melt the shea butter 30 seconds at a time in the microwave. Heat just till it melts. Watch it carefully. Don't "cook" longer than it needs to melt.
When handling the jar, be very careful not to burn yourself. The glass and the oil can get extremely hot.
While it is still hot, stir in the coconut oil, glycerine, and vanilla oil.
Cap tightly and shake for a minute or two.
Put into small containers such as jars from used cosmetic, etc.
Shake each one well again, about a minute.
Put into freezer and leave several hours. (This step helps it cool evenly. If it cools unevenly it often has a strange gritty texture.)
Remove from freezer.
After it thaws completely and comes to room temperature, you can use it. It should be more or less solid, but when you touch it, it will soften enough for you to take some with your fingers and spread on your heels.
Use generously on your feet (wipe any extra you have on your hands onto your elbows) and then put on your hiking or walking or bed socks.