Do you have a good layered haircut? I have thick wavy hair with more curls on the bottom as well, and it's crucial that I get layers all around my head or the top layer will look kind of limp. The top layer needs to be a few inches shorter, at least, than the bottom layer to make it spring up. Sometimes people will try to cut your hair like straight hair and be resistant to cutting your layers short enough, unfortunately.

I have only been doing this for a short time but I like using a sulfate free shampoo, not CO method. I think with wavy hair, it's common to need a real shampoo, just a gentle one.