I spent a great deal of my mid-twenties freaked out about feeding my husband. One of the first times I baked for him, I unwittingly used a vanilla extract that I later found out wasn't necessarily gluten free. I was SO MAD AT MYSELF. There are plenty of good GF vanilla extracts out there, but when I learned how easy it was to make, I vowed to never buy it again.
local co-op at ask them. Rumor has it you can buy beans online, but quality is hit or miss. I also purchased a case of 12 250 ml glass bottles about eighteen months ago and haven't regretted it.
So you gather those three materials. Split the beans down the middle, put them in the bottle, pour in the alcohol, put the top on, and shake.
I'm going to make up a bunch of these to have on hand as hostess and housewarming gifts. I might also give some of them away as holiday presents.