um. there are so many different ways to throw a misty, don't just call it ugly.
You can tweak out a grab, you can arch your back, or delay the last spin.
I'm working on double safety grabs in them - looks pretty sick because you're body gets so tweaked out.
Your problem is that you are looking at a misty as two different things going on at sametime - a flip and a spin.
You need to view a misty more simply as an inverted spin.
As you come up to the jump, get your shoulders prepared and a good stance. If you spin to the left, throw your right shoulder out in front of you and down - like you are trying to grab your left foot with right hand. This will automatically make you spin with it.
If you do this as I said, the misty 540 will come effortlessly.
MAKE SURE YOUR HEAD IS LEADING THE WAY. AND THAT IT IS GOING IN ONE SEAMINGLESS DIRECTION.
Pop, throw your head and your outside shoulder - same time - same direction.
If you want to spin more with it, then keep your head looking over your shoulder and keep your right shoulder following through.
Eat. Sleep. Breathe. Ski.