In reply to featuresforfeet:
I'v been warned, and seen it myself (unfortunately not in that order).
don't use fluorine (Teflon) based wax (inc NotWax)...
it'll leaves a trace layer on the skin glue, makes them a lot less sticky.
it'll happen less so if the base is well scraped, but my skins became noticeably less sticky, and my mate had a pair of skins that became unusable for the same reason.
I'd only ever use hydrocarbon wax, and even then the base gets well scraped.
(if you're not sure what wax you'll get from the service shop it's probably hydrocarbon; they tend to be cheaper)