it's straight up stolen from gymnastics. it's doesn't really involve a spin, per say - and it's super easy.
1: strong upwards pop before throwing forwards into the front flip motion
2: throw the front flip motion, but don't tuck instead keep your eyes looking down as your body swings around
3: as long as you threw it right and kept looking down your body will naturally "spin" a 180 as your foot go over your head which will now leave you "switch"
4: now you can tuck your knees in (or lay it out even more) to play with the speed of your flip, making sure you stomp.
Like a lincoln loop, you never have to take your eyes off the landing, meaning that as long as you commit to the flip, it is a really easy trick to land.
he's right. I didn't even think of doing these on skis cause I've really only ever seen rollerbladers do it in vert in like the '99 x games. but i was trying them recently and couldn't get enough height. they're really easy off diving boards though.