WAVY HAIR

I played around with my (Philips) hair curler today and i kinda like my hair curly. First off,my hair is really straight and really heavy,so curls never last long on me. And i hate that,because i really like my hair wavy. Even though i use quite a lot of hair spray,they are totally gone in 2-3 houres.

Do you have any good tip on how i would keep curls on? If you do,I'd be more than happy if you shared that with me :)