The mineral oil is used as a non-evaporating base to hold the essential oils. Start by pouring a 1/4 cup of oil into a measuring cup. Then, add 2-3 tablespoon of vodka. This won't mix naturally, so stir throughly to emulsify them. Next, add the essential oil to the mixture. Your ratio should be around 75% base to 25% essential oil. Stir thoroughly.