I found it easier to rev match in cars than bikes, but I learned it in cars first which may be the reason. What car do you drive? Some pedal arrangements are worse than others. Also, it helps to brake relatively hard so that the brake pedal is a bit closer to the throttle when it comes time to blip. Also, the term "heel/toe" is just carried over from a long time ago when pedals were further apart. You actually want to use the inside and outside edge of the ball of your foot. If you brake hard enough with just the edge of the pedal you might even hit the gas pedal with the outside edge of your foot inadvertently. It also helps to be using the higher RPM band, so you can just slam the throttle crudely and get the right amount of blip. At lower RPM you have to be more subtle, it takes finesse. I find it's particularly true with FWD, where a slight RPM mismatch can really unsettle the car. With FWD and low RPM, I can't rev match smoothly at all.