I've kept long hair for a long while now, but being a male who doesn't use hair products, I'd like some tips.

You could try a different shampoo and a really good conditioner. To me, the conditioner makes all the difference in the world. My hair is lower than mid back and naturally curly. But on the real though, long hair on dudes just doesnt look right. You should try to cut it... you may like it.