Personal Hair Advisor: First, check your products. Use a gentle shampoo to help regulate the oil glands and don't use anything too strong! That will be actually be counter productive since it will stimulate the oil by cleaning the scalp too much. Also try to shampoo every other day, rinsing on the off day. When you use conditioner, try applying it gently with your fingertips, keeping it only on your ends and avoiding the roots and scalp completely.
Then, if you use a blowdryer, avoid aiming the heat at the scalp to keep the oily look away. Towel dry before you blowdry to remove most of the dampness, then direct the blowdryer to the hair strands and roots.