The problem might actually be that you're not thinking of them as regular kickflips, one thing I always tell people is to approach them as regular kickflips that just won't work on a bad day and since most of the time they know how a regular kickflip works it seems to make everything that's wrong in their movement a lot more obvious.
Personal secrets of mine:
- shoulders completely parallel to the board, from the start and throughout the whole trick;
- big toes on both feet in line with the same imaginary axis that runs parallel with the board and right through the middle of the truck hardware, which translates as the big toe on the popping foot in the center of the tail (feels a bit like a duck stance) and the other big toe in the center of the front bolts. And then from the pop on, you use nothing but your toes.
Switch frontside flips might be easier to figure out at first if you have decent switch frontside 180's (which most people do, whereas switch flips are more straight switch ollie technique which most people miss) and are trying to figure out the flick, but I wouldn't necessarily recommend going out of your way to try them first just in case it might fuck with your technique (but they actually helped mine so what do I know).