Homemade Coconut Milk Shampoo

1/4 cup coconut milk (Like I said, you can either make your own, or use store-bought)
1/3 cup liquid castile soap (like Dr. Bronner’s)
1 tsp vitamin E, olive or almond oil
10 to 20 drops your choice of essential oils (I used lavender. Next time I think I’ll do something citrusy just for fun. :-)