If one partner has arrived late, have a brief conference between innings. Look sharp and dress the part. We've all heard that you are judged before you make your first call. This is VERY true. Spend some of your fee and replace those pants and shirts that have been around for the last ten years.
Perception is reality.
With runners on base, each occasion that time is given or a ball is fouled, the ball MUST be pointed back into play. The batter must be in the box and the pitcher on the rubber with the ball. I've had numerous pick-off attempts where, as the base umpire, I had no idea if the ball was live or not. Not a good situation. Also, a sharp pitcher will see you point the ball into play and immediately throw to first hoping to catch the runner napping.