swix wax school will show you everything you need to know. Just go to swixusa.com and click the wax school link and videos will show you what to do. THey don't have a freestyle section for tuning skis so just go into race.
it depends on what you want to do to the base. if u really want to clean all the dirt and shit out of it use a base prep wax and then hot scrape it (scrape before the wax dries). then put a running wax on it. if u just want it to run better use a base prep then running wax conventionally. neither way is "better" they're just for different things
bringin' back the circle game...
"Whoa you landed that backwards!"
-Random Race Weenie