for rails i heard a really good tip once.
imagine you are running up to a stationary skateboard and jumping on it (so that the board rolls forward), do it like that but with skis on.
and with spinning 3s, keep your vision and shoulders horizontal. dont look down. if you see someone whos pretty good, ask for help, most people like helping others. hope that help, good luck
and if you don't have a trampoline just find stuff like picnic tables bumpers and stuff like that to spin off