It's not necessarily true that while you grow your hair it has to go through that intermediate annoying stage when it's too long to look tidy and too short to style. There are many hairstyles for shortish hair, even for guys, which can help you not look like a tumbleweed. It will also do the growing hair good to be regularly snipped and styled by a professional.

If you've never had long hair before, it's likely to grow faster. This is why guys often have an amazing spurt of growth in the first year whereas girls have to be more patient. However, everybody's hair has a finite length. If you want tresses you can hide in like Lady Godiva and you hair doesn't want to grow that long, it simply won't, no matter how long you leave it - so don't be tempted to not cut it until it reaches the length you want. Have the ends trimmed and, for guys, your cat hairs (the little ones on the back of your neck) tidied up on a regular basis - about every 8 weeks or so. Otherwise you hair will dry out, the ends will split and the dead parts of every hair will climb up, ruining you hair until most of its length is frizz. This will make it impossible to style and looking always dry and unclean - not the effect anybody is trying for, I should hope.

Keep your hair clean and well conditioned. Dirty, greasy hair looks offputting, but it also grows less quickly. If you eat lots of fruit and veg you will give you hair the vitamins which will help it grow faster, smoother and thicker as well. Guys in particular tend to trade off the health of their hair for the speed of its growth, resulting in that frizzy uneven student ponytail which they think is cool but which is really not so attractive.

It takes a long time to grow your hair from a really short haircut - I'm talking years - but it's worth it for that one morning when you realize you need more shampoo in the shower... Or the first time you have to tie it back in order to tuck into a hamburger without it getting in the way... Or the first time someone runs their hand lightly through it and says "wow, you hair has grown so much!".