when im beat matching i cue the record in then bring it up to a rundabout speed as the one im mixing in to, then leave it for a couple of seconds to see if its accelerating or decelerating away from the allready being played track, then i adjust the pitchto corrospond to the other track. if the record is falling behind ill push it forward then once the tempo is locked speed it up slightly again so it wont fall behind and keep doing this until both records stay locked, takes about 30-60 seconds tops.

not that it really matters how your doing it though as long as its working, but i get the feeling this is being brought about as being "trendy" or somethin ?