I stop feeding after the Thursday night prior so the fish can fast.
Fish from tanks filled with rockwork, etc, that makes them hard to remove I'll net and move into relatively bare tanks in advance so it's easier to get them out the morning of.
I print and cut labels the night before. (I use packaging tape to secure the labels and keep them waterproof the morning of).
I don't use O2 personally, so I bag the morning of. Remember to not put in too much water - fish need water to only keep wet (provided you fasted them sufficiently) and air to breath. 1/4-1/3 of water in the bag is sufficient.
I take the time I have to leave, subtract 30 minutes for loading, 30 minutes for food/getting ready, and figure I bag around 8 bags per hour (everything double-bagged, double rubberband'ed). For someone who's new, maybe plan for 1/2 that speed of bagging.
Normally I'm up around 4am, because I get there really early to help setup and check-in everyone else's items prior to the start. Be sure to say 'Hi'.
