by side flip do you mean lincoln loop or a flatspin? this is a lincoln and Im guessing its what your talking about:
http://www.youtube.com/watch?v=Mr3rwQ7Du_s
solid pop, dip the shoulder and wait for the rotation to come around, dipping your shoulder before the lip will probably cause you problems because you will be off balance when you start the rotation. It really comes down to what feels best though, if you can do it on a tramp you can do it on snow, It just take more commitment.