My hair won't curl? How to curl my hair?

My hair is wavy and really poofy dry and brittle. I tried french braiding over night, i tried braiding over night, and also tried the twsting and then putting it in a bun thing. But my hair just doesnt cooperate because one time, my hair turned out SUUPER poofy and nothing was even curled there were like strands of hair sticking it. I'm afraid if i try it again, it'll just damage my hair and just make it worse.