to aerate one gallon of wort, simply shake the snot out of the carboy before you put the yeast in.
any more than that is a waste of effort.
i brew exclusively one gallon batches, in carboys, and what i do is pour about half the wort into the carboy, and shake the stuffing out of it for a couple minutes, then pour the rest in and repeat.
then i pitch the yeast, and give it a couple gentle shakes to get mixed properly, put in the blow-off, and wait about 4 - 5 hours for the fun to start.
In the fermenters: nada
In the bottle: nada
In the fridge(and the glass): nada
On Deck: anything i can think of