It helps if your edges aren't all that sharp, and commitment.
For tail butter, start the pivot with some speed, and put your weight on the tails, lean back a little.
Nose butter: kind of act like you are going to spin off a jump, use your arm to wing your body around, and put some weight on the nose tips, and lean forward, while trying to stay off the edges.
I'm not all that good at it but those are some starter tips to get you thinking. I feel like I should put more into this though. Some one will have it better for sure.