Do Not Do the Following (all observed this past week at the gym):
Don't . . .
. . . idle your car in the parking lot, blocking all entering traffic, just in case someone pulls out of a close parking spot.
. . . leave your workout towel on the machine as a claim and walk away for 10 minutes while you do another exercise.
. . . interrupt a trainer while he's spotting a client to ask a question. He or she will probably be glad to help, in a few minutes.
and finally, don't . . .
. . . sneeze, wipe your nose, and/or cough into your hands and then go right back to using the equipment.
Please, especially that last one!