Lower the brake pressure in the front by making the braking more biased to the rear of the car. If the car has a lot of oversteer, this can be compensated by adding negative camber, making the cars corning attributes better, and vice versa if it has little oversteer and more is desired. Also, lowering the car will help make it a little more stable in the corners. It can also be helpful to make the rear springs stiffer then the front ones, making the rear stiffer, so when the weight is shifted to the back corner it will make the car slide a little more. Note: This may not work for your style of drifting.