Welcome to GTP!
The best tip I can offer will (fortunately) make you faster - drive a smoothly as possible. Don't brake at full push all the time, and brake earlier. Ease the throttle on and don't slam the steering inputs. I used to have a real problem overdriving the car that way, and once I learned to really modulate my control inputs, I found myself going faster and going longer on a set of tires.
You can also switch down to a slightly harder compound, which will help your tire life.
Lastly, if you're wearing out the fronts, add some camber to help the front grip a little more and it will help with wear. Excessive toe settings also hurt tire life.
Good luck.