With fan kicks, prep with your feet together, but turnout your base leg just a little bit. Cross your leg over when you kick and make a full circle with your leg. 

 Make sure you are not dropping your shoulder down. Keep your shoulders back. 

Put your hands behind your back and lock your hands so your shoulders are back. Prep with feet together, plie, drive your knee up and swing it down like you are doing fans. This will help you learn not to move your upper body. Then add the full fan kick motion. 

For some added difficulty, you can do fan kicks into hinges. 

For an unhooked fan kick in a jazz routine, step to the corner with your foot turned out. Brush your leg through first.