Hello!
it depends on what youre trying to use them for. i personally like going with just the castor oil however if you want increased detoxification/anti-inflammatory support, I suggest frankincense. if you’re using castor oils packs for sprains/joint pain etc, helichrysum oil is INCREDIBLE for that. If youre doing it for stretch marks, I like using rosehip/rosemary and if you’re doing it for regular relaxation try using lavender (be careful lavender can be a bit irritating).
Let me know if you have further questions!