Start with Shea butter, available at some health-food stores but I get it at the anual African festival here in asheville.
Step 1: Liquids
Next comes olive oil, not too much since is will be too oily and ruin your shorts.
Step 2: Options
If you can't find shea butter you can use cocao butter as long as its 100%. Cocao butter is more solid so it might need to be warmed up first.
Bee's wax can also be used as a base, but not without some shea or cocao butter. The wax should be melted over very low heat.
Let me know if you have some suggestions.
Good luck and ride safe!