Straight spins problems

I can straight up spin 7s,9's and that stuff, but recently i learned how to misty seven. I'm having this weird habit where when i want to throw any spin 540 and up, I have the instinct to dip my shoulder forward and huck super hard, I have NO idea why this keeps happening!! any tips to break this habit? (note: I can 360 fine but when i have the mentality of spinning anything above a three I just set it way wrong) I feel like its all in my head and i need a way to keep spinning normally like i have known how for so long, but keep the ability to misty as well