Once a character is in the room, again, courtesy. Yes it's nice to be friendly, but if you happen upon a group of people engaged in RP, try and keep spam down to a minimum as much as possible. Do not walk in and proceed to make cutesy ooc comments, start ooc conversations, test out all the places commands, and constantly pass in and out of the room when you can easily bypass it. The best thing to do perhaps is pose a unobtrusive entrance, and then pause to get your bearings. If no one's doing anything, then great maybe you can initiate, but check. There are few things more annoying than when you're involved in a rather emotional conversation and someone spammily passes through the room 5 or 6 times and finally stops and starts making OOC comments. If they /are/ doing something, then perhaps you can join. But again, IC motivations, IC positions, IC personalities, IC descriptions, IC positions.

Try not to act until you have figured out what exactly you, as your character, would be perceiving upon entering. Don't automatically assume that because the desc/contents of a room are listed, that you automatically see and notice every detail. Very unlikely. Especially in places like Times Square, it is very unlikely that you will see and notice every individual player character in the area, especially amongst the crowds. Positions are very important to find out. Someone may be in an alley, off to the side, on the roof, out in the open, under a table. Do not simply walk up to someone and say 'hi' without knowing what it is they are doing at the time.

Give players present ample opportunity to pose position. If you walk into an area and a few poses go by before they have a chance to pose position, do not immediately assume you are being neglected. More appropriate would be for you to give them a chance to catch up, pose for you, and then pose yourself. Typing things out might take minutes whereas saying it in real life would take only seconds.