[crazy voyager]

for me when I work at the board (less often these days scince I ref now, I did it all the time before though) I usually start of with being sure who takes care of what, who's time keeper and so on. And I always have the time keeper notifing me when entering a new minute of play (scince the minute is to be entered next to the score in a FIBA score sheet)
I never drink or eat while working, I do that in the QTR pauses, never during play.
I always make eye contact with the officials and nodd to them when acknowladging there calls, esspecially when a foul's being reported. Then the official know I follow him, and he also knows that if I for some reason say "hold on" and check the sheet for something he can't keep signaling.
And if you lose focus, try to sit and comment the game (preferebly loud even though it's quite embaressing if people don't know why you're doing it)
then you'll notice you quickly get a grasp of what's happening and regains focus on the game.

Good luck!