Dance etiquette is the set of conventional rules which govern the social behavior of dance by its participants. Such rules include the way in which the participants should look and the way in which they approach, dance with and leave their partner. Etiquette can vary in its specification and stringency between different styles of dance.
The dancers move counter clockwise (from above) around the floor.
When things go wrong on the dance floor always apologize. Generally it does not matter who is at fault.
If you are moving more slowly than other dancers keep to the center of the floor.
If you are engaged in conversation move off the dance floor.
To cross the room either dance across the floor or walk around the perimeter.
Carry food and beverages around the perimeter. Wipe up your own spills.
While dancing, do not give dance tips unless asked. If asked, just give tips about what you were asked about. When engaged in giving a lengthy tip, or if you stop dancing to discuss it, move off the dance floor. And, above all, don't give that person tips again until they ask you again.
You can politely turn down a request to dance by saying something like "No, thank you. I'm sitting this one out." or "I'd be happy to dance with you later. I just need to rest now." If you turn down a request to dance, to be polite, it is important that you not dance at all during the dance in question. An exception to this would occur when you have promised a particular dance, a Waltz - for example, to someone else. Then you can politely explain your situation to the requester at hand.
Don't just dance with your favorite dancers. It's called "social" dancing for a reason.
It is always up to the follow, not the lead, to set the distance between the partners. However, if the lead feels like he is being held to closely for comfort or safety, they might say something like "If you move away a little bit, I'll be able to lead you more safely." If either partner is not being allowed to set what they feel is a comfortable and safe distance, they should feel free to say that they need to sit down to rest, or something else equally polite.