My DTD's are mixed race, with long thick super curly hair. After years and years trying to get their hair to look good, lots of different products, you name it, I tried it, the best thing ever has been this simple method.
WASHING HAIR:
Lots (I mean LOTS!) of fave conditioner all over wet hair, massage in, then de-knot with tangle teaser brush. Rinse out thoroughly. (Maybe every 5th or 6th wash I will use a bit of shampoo mixed with the condish to get rid of build up).
Next, smooth more conditioner all over the wet hair, massage in again and just leave it in this time, no rinsing. (I always plait their hair after this stage and let dry).
(For us the best condish for de-tangling and leaving in has been the blue Tesco 'herbal essence alike' conditioner - nothing else works as well. )
STYLING:
Only using a tangle teaser, a denman brush and a soft boar bristle brush for styling and detangling.
We now don't need to use any styling products at all. Hair only need spritz of water and maybe small splodge of same condish smoothed through and it looks lovely.
DEEP OILING:
Every now and then, I use warm olive oil/coconut oil, all over their hair, massage in, and plait overnight. Wash next morning using same method as above.