I too having this same problem. Let me what i do to reduce oil from skin
I wash my face,whenever i see oil on my face.
I use face-wash twice or thrice.
2 or 3 a week,i use face pack.
1.Try to keep your skin neat and clean.
2.Wash your face 2 or 3 times a day. but don't wash more than that.
3. Try to use oil free moisturizer products which controls the sebaceous glands that makes the skin oily
4. Keep a bowl of water in the fridge and splash this cold water on your face 3-4 times a day.Cold water will not only leave you feeling refreshed but will also tighten the pores.
5.Drink at least 8-10 glasses of water each day.Water helps flush out toxins from the body.
6.Try carry hand kerchief wherever you go. so that you can wipe your face whenever you feel it is oily.
7. If your skin has severe oil producing problem then better you consult doctor or beautician
All these tips are not special one, they are home made only which we do in our daily life. so there will be no negative effect