Some people their hair are dry and some people also their hair are oily,  if you have problem that oil build-up in your hair here is the tips that I have read that might help you.

What you need to do is after shampooing, rinse hair with a weakly steeped blacked tea. Tea contains an astringent-like acid called tannic acid, which can cut the oil. This is worth a try if you have oil build up in your hair this might help to reduce the build up & help look nicer as well.