well when i do fs switchups i jump the whole way and when i do bs switchups i tend to keep the spin going a little and hop more like 100.. thats just me though..
best thing to do is to like turn a few degrees, maybe like 50 or something, hop round so you tips clear the rail, then spin the rest on it. Its a switch up, just easier when your learning
When i first learned i like came up to the rail like ready to pop just stepped onto the rail and popped really fast and tight 180s swups are way easier than you may think