Don't be "that guy"—the one who leaves the locker room a mess, who sings in the shower, who struts around al fresco, or who does whatever the heck he pleases at the gym! Here are some simple rules of locker room etiquette to ensure you're not the guy who everyone hates:

1. Get in and get out -- You're at the gym for a reason: to work out. You're hitting the locker room for a reason; to change into your workout clothes or to shower and change after your workout. Make it a quick stop!
2. Look around -- Ask yourself these questions: Does someone else want to use the mirror? Are you standing in the way of someone else's locker? Are you occupying all the bench space with your clothing? if you are, be conscious of those around you and cut it out.
3. Keep your clothes on -- The locker room isn't a place to be nude—save that for your house! Get dressed and undressed as quickly as possible. Your fellow locker room users will thank you.
4. Clean up after yourself -- Throw dirty towels into the right bin, discard any tissues or paper towels, and wash your toothpaste and spit down the sink. Leave no sign that you were ever there.
5. Bring a lock -- Want to ensure you get the same locker every day? Bring your own lock to the gym, and use it to padlock your locker. No one else is going to take the locker if it has your lock on it, and there's a much lower risk of your stuff being swiped by accident.
6. Turn off your cell phone -- You're in the gym to work out, so turn off your phone (unless it's absolutely necessary). No one wants to worry that you're snapping pictures of them at the gym, so keep your phone off and stowed while in the locker room. If you have to take a call, step outside.
7. Keep your eyes and hands to yourself -- This should go without saying, but the gym is NOT a place to get handsy or make eye contact with others. Don't slap butts or touch anyone without clothing, even if they're your good friend. Keep your eyes focused on yourself, and don't let your gaze wander.
8. Limit conversation -- A nod is usually enough to communicate with those in the locker room with you. Say "hello" if you must, but avoid long conversations unless everyone involved is fully clothed. Watch your topics of conversation as well!
9. Showers aren't urinals -- Yes, you may pee in your shower at home, but DON'T do it at the gym! Pee in the urinal, and wash in the shower. Do not confuse the two.
10. Wear flip-flops or sandals -- When you do, you show that you care about your hygiene, and thus the hygiene of those around you.
11. Use the blow dryer for your hands -- If there is a blow dryer in the bathroom, resist the urge to use it for any body parts besides your hands. No one wants to see that!
12. Limit grooming -- Do your hair, brush your teeth, splash on some cologne, and spray deodorant--these are the only forms of acceptable locker room grooming. Shaving, clipping your nails, and manscaping are NOT cool!
13. Respect personal space -- Don't hover near the other people in the locker room, especially if one of you is only partially clothed. Give people their personal space!
14. Don't take selfies -- Yes, you may look great, but the locker room is NOT a place to snap pictures of any sort.
15. Tip your locker room attendant -- If there is someone in charge of taking care of the locker room, tip them well. They're not making anywhere near enough for the crap they have to put up with for cleaning up after hundreds of full-grown men!

Follow these rules of locker room etiquette, and you'll get along with your fellow gym-goers just fine.