the only reason butters or hard to do is kuz its againts everything you learned skiing.
tail butters
you got to picture that a butter is just not a spin , the way it works, is that you want sit your self over your tails at a point were your nose are in the air (around 5"0) and there's only your heels and tails touching the snow,kind of like doing a 180 whit your toes passing over your heels, not too far away cause you still need some pop to get out of their, feel it on a flat spot w hit no speed and you'll see that their a spot on you tails where you can rotate on the snow easy. then when you have the feeling right , start switch , proceed whit a butter , and when u are at 180 whit the weight one the tails , you just need a little pop to get out of that position and use the pop of your tails to jump higher and spin more or pop on a rails...
let me know if that's enough or you want some info on nose butter , which are harder