Ensure your glass bottle is clean and completely dry.
Using a kitchen scale or measuring spoons, measure out each oil: 1 oz jojoba, 2 oz avocado, 2 oz olive, 1 oz castor, and 2 oz hemp seed.
Pour the oils into the bottle using a funnel to prevent spills.
Add 15-20 drops of essential oil, if desired.
Seal the bottle and shake gently for 30-60 seconds to combine.
Label the bottle with the date and store in a cool, dark place. Shake before each use.