Hi, what I do to get my hair to grow (it seems to work for me) is to use as little heat as possible on it. Be gentle when combing your hair. I trim my hair every now and then on the bottoms to get rid of any split ends. Also in the shower I make sure I use good shampoo and conditioner that keeps my hair moisturized and doesn't dry it out. (Do not wash your hair everyday) and when I am in the shower I use a shower comb to help the shampoo and conditioner get to the roots better. I hope this helps you!
I don't know if this works all the time, but I was once told to actually trim my hair regularly (just to cut off split ends or just to regrow it for that matter). Just an inch every 2 weeks, at least. Well, this works for me. :)