I don't measure anything--I just add what looks like will be enough for one application...
I melt some avocado butter and shea butter using the water bath method (put in a thick glass or Pyrex bowl and add that bowl to a pot of boiling water), add some Proclaim Natural 7 Oil, palma christi oil, jojoba oil, virgin coconut oil (from healthytraditions.com), kukui nut oil and kelechi hair oil. I heat it all up again using the water bath method, apply it to my hair and wear my Micro Hair Cap for about 20 minutes.
I do this treatment on dry hair before I shampoo. It makes my hair feel softer and much easier to comb afterwards. I try to do it every shampoo, but I don't always have the time.
I get most of my hair oils from pennherb.com, nasabb.com and selectoils.com The health food stores around here don't have high quality oils...