One thing I see people post occasionally is putting your hair in a tight pony/braid/bun will help it grow. This is absolutely NOT true, and especially don't sleep in it! That will only cause more breakage and damage, as you roll around in your sleep. Use a satin pillowcase and bonnet to keep your hair out of your face, that will keep your hair from breaking while you sleep. It will also keep your hair from getting frizzy!
Another thing I've seen is using lemon juice to lighten hair/control frizz if added to shampoo. Also probably not the greatest idea! The acidity from the lemon juice will cause nothing but more problems in the frizz department, not to mention will dry your hair out like crazy. It will probably also decrease the effectiveness of the shampoo. It is NOT meant to be used on hair any kind of regularly and I wouldn't do it on my own ever. That's just me. I wouldn't suggest it for a lightener because again, it's going to dry it out and also, it's not likely to be an even result.
Make sure you are using a good deep conditioner once every week or two. And get yourself a good argan oil or some Moroccan oil and use it after you shower on your damp hair working it from the ends up toward the roots. Moisture is key for healthy hair!
NEVER brush your damp hair, wet hair is more fragile and breaks easy, so always use a wide tooth comb to detangle once you're out of the shower.
Instead of a towel, use a t-shirt to dry your hair. Towels only cause friction which cause more breakage, t-shirts are a lot softer and easier on the hair.
Avoid heat and damaging products as much as possible! My hair thanks me for not heat styling hardly at all anymore. Plus my hair is a lot less frizzy! My hair feels thicker, my curls are beautiful, it's softer and just looks and feels better. Plus, no split ends! Which ends in hair growth for you.
Lastly, and I know you don't want to hear this necessarily, but get your hair trimmed somewhat regularly. I usually get my hair cut 2-3 times a year, unless I have a shorter cut to maintain. Just to get the dead, dry ends off! Keeping your ends healthy is imperative to growth. If your hair is full of split ends, it's a lot more prone to breakage so, not only will your hair be uneven possibly, but it won't grow as well. I'm a cosmetologist so, if anyone has any questions, feel free to ask away! I'm here to help!