[Miss Mad Scientist]

-Coconut oil twice weekly up to 8h
- Avoid heat
- Wash your hair up to 3 days weekly
- invest in a good shampoo and conditioner , best 0 paraben
- Change shampo and conditioner once it's over = i.e hydrating shampoo , then strength shampo. Also mix the conditioners, i.e one day hydrating one next day color-protector one ( I do have 3 conditioners at the same time that can last bout 8 months)
- eat properly
- don't smoke
- don't drink alcohol
- drink plenty of water
- multvits twice a year
- eat healthily 
- use argan oil in your scalp twice a month
- chop off your hair 3 times every year (healing the endings)
- don't wash your endings every single time you decide to take a shower.
- biotin tablets for 3 months per year

Ok, out of all threads, I feel like I have to reply on this one 
I just measured for you guys:
My hair is 91 cm long (35.8 inch)

and super healthy!

These tips sweetorange gave are really awesome! I would stand by them, and actually do almost of these myself.

Also the Inversion method is amazing, as told here before. Look up on youtube how to do it.
Besides that, buy a spider head massager, it is the best, and so relaxing.

To prevent damage, buy microfiber cloth and only dry with that after you have washed with that.

Airdry your hair with a cooling fan, if you want to speed up the drying process a little. But never use heat!

Next, one of my biggest secrets: buy a satin pillow case. At least 8 hours a day you spend breaking your hair on a cotton pillowcase when turning while asleep. Satin doesn't do that to you.

Also, don't go to your hairdresser more than once a year. I haven't gone to one in years, and it looks superhealthy. Buy hairdresser scissors and while watching tv or anything, grab a section of hair and go through each of them and cut out the individual hairs that are broken.

If your hair is super damaged or you really feel you need a haircut. Buy aPhogee two step protein treatment, and you'll see after you are done, you don't need a haircut anymore
I use it every 2 months

I am sure there are some more things I do for my hair that I just can't think of now. But this should get you started.

Love, Ellen

Oh and added bonus: satin pillow case also gives you less wrinkles and acne