Re: oily hair
Are you using an appropriate shampoo? A clarifying shampoo or one that is for oily hair can help. I use Suave Clarifying shampoo and it helps to control oiliness so that you don't have to wash your hair everyday.
Also, frequent brushing of hair is not recommended because the more you brush.....the more your natural oils get circulated throughout your scalp....making hair look greasy/oily.
Make sure that you're doing the basics such as taking a multivitamin, eating a healthy diet, getting sufficient sleep. The health of our hair and skin also depends upon these fundamentals.