Of course, eating a balanced diet and drinking plenty of water.
I could never get my hair past bra strap length. I've learned quite a few things in the past year and now my hair touches my waist.
1. Clarify all the silicone products off your hair, so that you can see any actual damage. Silicone does a great job of 'gluing' your split ends together.
2. Trim off the damage. I wet my hair, then apply some cone-free conditioner to the length and ends and leave it on. I use VO5 conditioners, they have no silicone. (the fruity ones) I use a mild sulfated shampoo (none of the popular products), and dilute it with water in an applicator bottle with a nozzle. Shake it up and the nozzle lets me get all the foamy shampoo right on my scalp. You'll find you have more than enough lather and it cleans just as well, but is much gentler on your scalp. Harsh full strength shampoos strip all the oil from your scalp and in turn, your scalp will work overtime to produce the oil and then much more.
I rinse well with warm water and then apply a 'richer' cone free conditioner all over, not getting any on the scalp.Two of my favorites are Nature's Gate Original Herbal and Sebastian Volume. The scalp needs to be free of any waxy,oily products. I got rid of my oily scalp by doing this and I no longer have to wash my hair everyday. I put a plastic hair cap on , leaving the conditioner on while I finish bathing. Then rinse well with warm water, followed by a cool/cold rinse to help calm the cuticle and promote natural shine.
3. I've learned to let my hair air dry most of the time, saving the use of a blow dryer for special occassions. No flat irons or curling irons. I've learned many new cool up-do's and in the process my hair has grown like a weed. Pretty awesome for an old lady.
4. If you want coloring or highlighting, go to a professional. I get my roots touched up every two months and have a microtrim twice a year. I have no split ends. The microtrim mostly shapes my hair, it grows in a 'u' shape.
My avatar is my hair, except it is about 2" longer now.