Find a large, abandoned parking lot. Turn wheel, mat the accelerator.

Lather, rinse, repeat. Since you don't care about the existing tires, and you know you won't break the diff, there's nothing to lose. You'll get a good feel for the way the car behaves as it exceeds the limits of the traction circle. Consequently, you'll know the correct angle to hold while countersteering, and will be able to ride the fine line between drift and spin.