-When making a character, follow Sergeant Johnson's advice; "they may be tough, but they ain't invincible."
-If your going to interact with someone else, like if your next post is gonna have someone else's character in it, discuss it with the other character's/s' owner.
-If you're going to make an rpg based on an established universe, say Star Wars, originality maybe allowed, but try to make it something that may seem to be canon. Example, someone makes a Halo rpg that deals with after Halo 3, acceptable. Someone makes a serious Halo rpg where Hitler is leader of the Flood that use flowers to poison Australia and Spartans must shoot snuggies at them, not acceptable.
-Make your posts easy to read, no L337 speaking.
-Don't boot old rpgs that no one has posted in a relatively long time. It gets irritating.
-Read the rpg rules before you join.
-If you're going to have to leave an rpg, try to mention it instead of leaving other people waiting for you to post.
(More might be added if needed)