I want to teach some adult students how to make their own massage lotion (or cream). I'm hoping for a very simple recipe where they don't have to consider many variables(pH etc), something they could use professionally, and is a sturdy enough formulation that they can tinker with (change the slip and glide, add vitamin E/fragrance etc).
Right now I'm considering multipurpose ingredients like BTMS-25 to combine with their Jojoba or Coconut oil, and then use a catch-all preservative like germall plus. Some sort of mango/shea butter if its needed.
Does anyone have better suggestions?