My hair used to be naturally curly, but now it's just wavy and limp. Help?

i don't want to get a perm, but i used to have long, full curly hair, now it's just limp and wavy and it's about a little longer than shoulder length, i reeally miss the curl and i try everything to get it back to the way it was but alls itdoes is kink and lay flat...any help or advice?