Have an appreciation for and knowledge of the band that is playing and the type of music on display at the concert. Many moshers are strong supporters of the band, the music or both.
Respect non-moshers wishes not to mosh. Not all concert-goers are there to mosh. Some get as close to the circle as possible without going in just to enjoy the action. Others go to the concert simply just for the band. Don't shove anyone into the mosh pit. If you accidentally slam into someone who is not moshing and knock him down, pick him back up quickly, briefly see if he is OK and continue with the moshing.
Avoid wearing any kind of sandals in the pit. Wearing sandals will leave your feet prone to either being stepped on by someone else or cut open by remnants of a broken beer bottle on the floor, not to mention the lack of traction they have on the ground. Sneakers and boots are the recommended footwear for slam-dancers. Also, try not to step on any person's toes in the pit if she is wearing sandals.
Do not participate in what is called "hardcore dancing," which is when moshers swing their fists and legs as if they think they are Jet Li. This practice could seriously injure an outsider. Mosh Pits are for running around, slamming your bodies against each other and having fun doing so. Additionally, other moshers could ridicule you if you are hardcore dancing.
Make the acquaintance of other moshers. After the song ends, strike up a brief conversation with the guy next to you about the concert, music, experience or anything related to them. Don't make it long, though. The next number will come shortly.
Don't over-imbibe alcohol. Too much of it could lead to making reckless and possibly criminal decisions, not to mention that the overly inebriated concert-goer isn't looked upon favorably. If you want to drink, have a beer or two and make sure you finish your indulgence when the band before the headliner finishes its set. That way, you're ready for the action without feeling queasy.
Help your fellow mosher out. If he happens to fall down during the moshing, quickly get him back up and continue with the festivities.