This is a nice simple recipe for about 4 oz of natural homemade deodorant. The base recipe is only three ingredients, but I've included some common modifications for what some find a more luxurious end product.
4oz Simple Natural Deodorant (W/ Modifications):
-1/2 Tablespoon Baking Soda
-1/8 Cup Arrowroot Powder (Cornstarch works but arrowroot is preferred)
-1/4 Cup Coconut Oil OR 1/8 Cup Cocoa Butter + 1/8 Cup Shea Butter
(Some add about five drops of Vitamin E, but I tend not to. You can also use up to 40 drops of essential oil depending on variety and skin type, I err on the side of less for safety and subtlety personally.)
Process:
In any suitable container, gently melt your chosen fat source or sources to a liquid state.
Discontinue heating and add your Baking Soda and Arrowroot Powder (or Cornstarch).
Evenly stir your solution as it begins to cool, adding your Vitamin E and/or essential oil now if chosen.
Transfer your well-blended liquid to one or two containers and allowed to cool before sealing.
All of the ingredients have pretty good shelf life so you end up with a nice decently shelf-stable product which will stay workable and nice at room temperature for a good time to come. Schmidt's natural deodorant is made using a similar formula. I use my hands to apply after showering, but a popsicle stick should work well enough if you prefer an applicator. Enjoy!