During the classic "End of Round" (EoR) procedure judges report to a central hub of information, the Scorekeeper, or more likely a proxy for the SK who has a printout of Delinquent Matches which are still playing when time is called in the round. I'll have more to say on another occasion about various ways to improve this task, but today's tip is about as simple as it gets.
When the EoR judge assigns you a table number to go scout out and you pass other judges coming back to the hub with match result slips, call out the table number you've been assigned.
"Hey, do you have table number 56?"
If they answer no, you keep on moving towards table 56. However, if they answer in the affirmative, stop, turn around, (do not pass Go), and return to the EoR judge for another assignment. Congratulations! You've just saved yourself a meaningless and time-wasting trip to table 56, which in case I forgot to mention, happens to be at the opposite end of the GP hall.
Today's good practice helps save your judge legs, optimizes your time, and preserves judge resources throughout the day for the tasks that we actually care about, watching games of Magic, not walking to tables where the players stopped playing Magic one minute ago.
If you're coming back from a table with a result slip, you should also get into the habit of calling out what table(s) you're coming back with to judges that you cross paths with, spreading this good practice from both sides of the traffic.