Race cars used to have non-syncro trannies, so the drivers were pretty much forced to learn double clutching, and heel-toe techniques. Nowadays double clutching is just a novelty, even most truckers do it the lazy way and float gears...DON'T they PQ
Your pedals should be optimized for good heel-toe position, it makes it SO much easier. The throttle should be close to the brake (right to left) and when you're on the brakes, the brake pedal height should be the same as the gas pedal...A quick tap with the right side of your foot on the gas pedal and voila! rev and downshift!