I make my own Vanilla using 1 cup Bourbon and 2 slit vanilla beans. How about your own Kahlua using coffee and vodka.
Mint is a good one, but you need a lot of it, which is probably no problem if you have let it run wild in your yard.
I don't have much need for extracts, except for the vanilla, but I do make my own condiments, rubs, sauces, and such.
Support bacteria. It's the only culture some people have.