Most Helpful Guy
Hair's made of protein, so avoid food or drinks like coffee that hamper protein absorption, exercising produces testosterone, which is good for hair growth. I'd stay away from the cosmetics if you want your hair to be natural.
Most Helpful Girl
I had the same problem a few years ago, my hair never grew as curly as it used to anymore. You can always curl the top (or even everything) with a curling iron if you want it to look good and even. Don't forget to add hair mousse or hairspray to hold everything in place so you don't end up with wavy hair.. Unless that's the look you're going for.