The following is meant as a guideline and by no means a set of ironclad "rules". It is intended to give an idea of how to help make you a popular dance partner.
As in any social situation politeness is the name of the game when interacting with others. Always being kind and courteous will make you that sought after dance partner you hope to be.
Dancing involves a lot of close contact, so personal hygiene is paramount. Keep in mind first impressions last a lifetime. Breath mints/gum are always appreciated. Cologne/perfume, when used sparingly, is an excellent choice.
Asking Someone to Dance
Having been based on traditional lines, it is customary at most functions for the men to ask the ladies to dance. However it is perfectly acceptable for the ladies to ask the men to dance as well.
When you ask people to dance, ask politely, even if you know them well. Snapping fingers, nodding toward them or waving toward the dance floor are not acceptable methods of asking people to dance. Walk up to them, look them directly in the eye, and ask them to dance politely. From there, escort them onto the dance floor and dance with them to the best of your ability. Following the dance please thank them for the dance and escort them back to their seat.
When Asked to Dance
It is considered basic politeness that when asked to dance at a function to always answer "yes". If you absolutely must not dance with this person for some reason offer a polite excuse and then do not dance that particular dance with anyone else.
On the Dance Floor
It should be the objective of each of the ballroom dance couples on the floor to avoid collisions. The man, who is customarily in the initiating (lead) position, should never charge forward without thought of his partner. He should manoeuvre the best he can, knowing his partner will trust him to keep the dance partnership out of danger.
The lady, customarily in the responding (follow) position, should help keep track of dance floor traffic and indicate to her partner if he is about to back into someone else.
On the very crowded social dance floor the dancing should be kept more compact. If either partner does end up bumping heavily or stepping on someone, apologize and move on. Should you be on the receiving end accept the apology and continue dancing.
Remember that it helps build your skill to dance with dancers of all different levels from beginner to advance. Only the most selfish of dancers will always want to dance with someone more advanced. Dancing with someone less advanced will help develop your skills as a dancer. Fear of dancing with someone who is a better dancer can only hold you back as well.
Try to contribute positively to the social part of the event. Try to dance with as may partners as possible if you arrived on your own. If you have arrived as a couple it is always polite to dance with others half the time.
As a new dancer never be ashamed of the fact that you are new. Everyone started as a new dancer and, despite what some people might say; ballroom dancing is a learned activity, not something one is "born with". Of course everyone learns at different speeds and has different aptitudes, largely based on the activities they have pursued before. But it is the tenacity in pursuing the learning that truly makes the difference. The only difference between a new and an advanced dancer is training and time in skill development.
As an advanced dancer it is important to remember what it is like to be new and to make new dancers feel welcome.
After you have been training in your dancing for some time and you begin to gain a certain amount of dancing skill something happens to you -- you unwittingly become a 'dance ambassador' of sorts. It is difficult to say exactly when this will happen, but it is usually when people start to notice that you are quite good at what you are doing.
Because you have acquired a certain amount of respect for your attained dance skills people start to look at you as a representative of the community that you are "from". Non-dancers will see you as a representative of the dancing community in general. Other dancers will see you as a representative of the dancing school in which you have taken the bulk of your training, the dance teacher(s) that you have worked with, or all of the above.
Dancing is sometimes referred to as the "universal language" but remember it is not only your dancing skill that is speaking for you. Your attitudes toward others as fellow dancers, dance partners and other couples with whom you share the dance floor is just as important. Remember to treat everyone with courtesy and respect.
Positive inferences based on your behaviour reflect on more than just yourself and, as such, one of the greatest compliments you can pay your school or your teacher is to always conduct yourself well in a dance setting. Remember that your behaviour reflects on them as well.