im regular and what i did to learn was put my back foot along the left side of the brake at an angle and just jump and straighten out your back foot so it flicks the brake. then just use your wrists to send it around
I find them easier if you kinda kick using your back foot in a forward diagonal motion, and don't try to force them around, it helps you get a better feel for them. But yeah, just keep practising them when you're not working on other tricks.
when you pull up, kinda of pull up with your toes hanging off the deck. when you do that your feet should come off the deck and it will naturally start the rotation of a heelwhip, then its just all arms