[just another ref]

I think this applies in every game, but is magnified tenfold when you work alone. Don't be afraid to shrug your shoulders and say "I don't know because I didn't see it."
Don't make a lot of random calls. If you didn't see why 3 players fell to the floor in the lane, it's a no-call. If you look away from the ball and when you look back the ball is up in the bleachers and you don't know how it got there, go to the AP. etc. 2 people cannot watch 10, so 1 person alone is kinda up the creek. Don't try to do more than you can do.