The carrier oil choice is determined by the therapeutic effect you are seeking.
For example, you mentioned jojoba and also olive oil.
Adding jojoba oil makes sense if one has oily skin.
Olive oil becomes rancid too quickly and because of this
I would not suggest it if the product requires much of
a shelf life; I also don't like the smell.
There is a lot to know.
For example, shelf life can be extended when
Vit. E is added as that is a natural preservative.
Your essential oil should last a long time but it needs to be stored in a cool place in an amber colored glass bottle.
Again, the choice of carrier oil depends on the therapeutic benefit being sought and we need more information to make helpful suggestions.
Arlene Batz, CPE: Educator, Board Certified Electrologist, NYS Licensed Esthetician. http://endunwantedhair.com