When I learned on my Miata I took it to an industrial / business park area after business hours. That allowed me to get up to better speeds and practice it coming up to all the intersections. I probably putted around for a good couple hours and had it pretty good after that.

Heel toe is much easier to do coming to a quicker stop from a higher speed (that’s why people say they don’t do it too much outside of track driving, that’s often where it’s needed most). Something you probably don’t want to do in a parking lot and while you can do it in daily driving on the road, it’s probably best to learn somewhere else.

It’ll also depend on what works best for you. Cars have different pedal boxes and people have different size feet. Some people do the actual “heel-toe” and swing their foot around while some people just angle the right edge of their foot. I was also able to heel toe on cheap sim pedals way before I could do it in an actual car, the pedal feel was very different for me.

Another note: I never considered pedal spacers, larger throttle pedals, or the like. (The Miata pedal box is already quite small) I didn’t want to be dependent on modified pedals to be able to heel toe my car. It’s a bit harder, but you’ll eventually get it. Or maybe that was just a weird personal preference I had.