I have curly hair, it's below my shoulders. The best advice I ever got was to not wash it too much. Once a week I use shampoo, the other times I use only conditioner, rubbing it into the scalp with the pads of my fingers and rinsing well. Also, I always run a little conditioner through my hair and leave it in before I get out of the shower. Squeeze your hair into a towel, do not rub it, to towel dry.
Try not to use a hair dryer. "Plop" your hair on the top of your head with a clip and let it air dry. Don't brush your hair unless you are straightening it, use just your fingers or a wide tooth comb.
Most of the de-frizz products do work, but they work best when applied to wet hair. Also, get a good cut from someone who knows about curly hair and how to layer it properly.
I got a lot of good advice here:
http://nopoohair.blogspot.com/
but I do like to use shampoo occasionally, I just don't use a lot and only on the scalp, I don't lather up all my hair.
Oh, and because I don't use a hair dryer, I only need my hair cut twice a year, because I never get split ends with this method.