I use it as a moisterizer on dry hair, but can also be a sealant. (Kinda like how Coconut Oil is) This makes the hair feel very soft! I melt it halfway (Semi solid consistency), rub it between my hands, and massage through out my hair.
Of course you can use it on wet hair as well. If you want to use a leave in, I would apply that first, and then use the shea butter. Hope that helps!