Because there are multiple people on the dance floor, dance etiquette helps to ensure that everyone has a good time. This applies to lesson time, practise sessions, and dance parties.
Be courteous and respectful. This is the basic principle of dance etiquette.
Conversation should be off the dance floor. If you need a discussion, take it off the dance floor. Dancers are constantly moving around the floor, and you don’t want to be blocking them.
No uninvited advice. Don’t comment on mistakes and give suggestions, unless you are asked to. Unless that is your student, leave the teaching to the teachers.
Keep the floor clean. If you accidentally spill something on the floor, clean it immediately.
If you bump into someone or step on someone’s toe, apologize. If someone bumps into you or steps on your toes, smile and don’t get angry.
If you want to cross the dance floor, walk around the parameter. Don’t cut through, as it disrupts the flow of other people.
Don’t film or take pictures, unless permission is given by the organizer or the teacher.
Maintaining personal hygiene. Make sure to take a bath, brush your teeth, and give your partner a pleasant experience.
Slow dancers should move to the center of the room. So you don’t clog up the main line of dance.
There are many websites giving different advice on dance etiquette. I only mention some of them here. These are the common issues I see on the dance floor, and I think they will be useful for beginners.