The smaller the kite (less powered), the easier, as long as it isnt so small you can barely foil, then it become tricky again.
Some prefer to use a harness with a sliding hook to be able to twist more upwind (I dont like it, got one but dont like the sloppy feel eventhough it in theory might help with my "stiff" old body) so can also help.
Keep the kite high so it wont run away with you even when going lower toeside than heelside (we all do that, go lower and less efficent)
Dont downloop the kite - fly it up and over so you wont get the high speed acceleration at the wrong times and end up with kite low.
As said - practise practise practise so you learn to have the kite at the right place at the right time, and you can ride any course toeside: upwind, halfwind, broad reach, deep downwind