After my hair is dry, I put about 3-4 drops of jojoba oil in my hands and rub my hands together well. Then I rub the oil all over my hair from the top of my ears down. My hair is BSL, coarse and prone to frizziness, and the oil makes my hair soft and smooth and shiny. If you have thin hair you may only want to put in 1-2 drops of oil.
In the above, instead of jojoba, some people like to use coconut oil or shea butter. The best kind of shea butter is unrefined from Africa with the healing properties intact. You can use a small amount as a leave in to make your hair look soft and shiny, or overnight as a conditioning treatment.
If leaving overnight, saturate your hair, put in a shower cap, then wash upon wakening the next morning.
After I wash my hair, I like to use clear Aloe Vera gel (not the green color) as a leave in. This takes care of the frizzies. It also adds some body and curl definition. One brand I like to use is Fruit of the Earth.
I might occasionally put a small amount on the canopy of my hair for frizz control also.