As far as "growing fast", I actually think my hair grows sort of slow, but I'm impatient.

Part of it may be that my hair is super straight, like a pin. There is not a bit of wave or curl to it at all.
As for my tricks on getting it to grow...here's what I do - I don't over process my hair (which leads to better growth because of little or no breakage. I rarely use product, maybe just a bit of hairspray on a daily basis or some goop of some kind (gel, texture cream, etc.). I don't wash my hair a ton, due to wanting to keep the color bright and also I don't want to dry it out. I wear a lot of bandanas. I don't know if that helps, but it might. It sort of protects my hair from the elements, I guess.
I'm sort of thinking if my hair really does grow quickly, I might be lucky, but then again, most of the time, I chop it off, anyway. My hair is so straight and fine, it doesn't really look right once it reaches a certain length, which is really past my chin. After that point, I have to do a lot of styling to get it to look good. Ugh, I hate that, so I don't really bother & just keep it short.
PS The first pic is me at work. Thought you all might get a kick out of that. It's where I do my *evil* --- *cackles ominously*!!!