The backside 180 is one of those feel good tricks and also has many variations.
Learn this trick first by starting on the flat terrain with your board off. First getting the timing of the pop using solid flexing extension movements in both legs is key. Then focus on using your upper body to create the rotation through the spine first stating open then rotating towards the tail. Now put it together trying to land softly by flexing your legs on impact. Then repeat this whole thing again with the board on still in the flats and not moving.
Now while traversing across on your toe edge try just some simple hops at first. Then try doing the 180 on the ground by rotating your nose of the board up the hill and the tail down whilst changing edges to the heel side and riding out switch. Remember to keep your eyes back toward where you came from until all the rotational movements are done.
Then you can try to slowly blend them together by doing the hop and quickly the pivot. Now try starting with only 90 degrees of the rotation and then try doing the second 90 in the air.
Eventually you will try doing the full 180 first across the hill and then when you’re comfortable, down the hill.
Then try some different variations such as Ollie, Nollie, and even late backside 180s. Try doing then off cat-tracks and roller as well as the jumps. The bigger the feature the slower the rotation. Remember to always spot those landings cause this trick is quite blind!