Up and down, the key as the others have said is chopping the throttle to unload the transmission. On the up shift if you preload the shifter you'll find that it'll slip right into the next gear when you chop the throttle. Down shifting is a little tricky, ya gotta blip the throttle to give the trans that moment of unload to shift in.
Play with it a little, you'll get a feel for what works and what doesn't. The trany is pretty tough but don't get crazy and try to jam it. Like I said it'll slip right in if you're doing it right.