flyingcab said..
riding toeside you will struggle to ride upwind as much as heelside
having your waist harness a little looser so it can slide around will help a lot as this will stop the kite from "twisting" you back to heelside
Having a seat harness is a complete write off unless you have a dynabar or something similar
Agree with flyingcab. The secret to toeside is getting the pull from the hip. It's also all about practice and lift the heel on your back foot and get the weight over the balls of your feet. You'll need more weight on the front foot than you think too. Once mastered it is the first step to big bottom turns in the waves.
I started with a dynabar but now just use a piece of rope and a shackle.