Heel and toeing
Heel and toeing is not actually done with your heel and toe!, your foot is supposed to rotate between your ankle and middle toe, the outer edge of your right foot blips the throttle and the inner edge (the ball of your big toe) presses the brake. H&T is used to raise the engine revs briefly either aid gears engaging or to smooth the effect of the clutch being released, as a result of the matching of road speed and engine\gear speed.
To get practicing, try braking only with the inside of your foot keeping the rest of your foot clear of the pedal, this will soon feel quite natural. then when at rest press the brake and rock your foot to blip the throttle, this is best done at traffic lights psyching out the guy next to you. once it feels natural try it on the go on a quiet road, doing both together is quite easy getting a consistent braking pressure and strong enough blip is the art.
I heel and toe (and left foot brake) all the time of the road and in any car. in fact with a good gear box your can brake and change down clutchless with only one foot (the blipping easing the down changes under heavy braking).