Milongas have a set of rules allowing for comfortable dancing even in a full hall. Below is the list of the most important ones.

- Mirada and Cabeceo. It is a custom to invite a lady to dance using eye contact, mirada. Lady who wants to dance scans the hall. If her sight meets a man who she doesn't want to dance with she simply looks away. If she does want to dance with him they exchange a nod, the cabeceo. She then remains seated while he crosses the room and takes her to the dancing floor. Running towards the man may be confusing because the cabeceo might belong to a neighbour woman.
- It's not necessary to start dancing right away. On the contrary, the couple should exchange a few words in order to 'break the ice'.
- You should better start dancing with the beginning of the music phrase.
- Keep the flow whilst dancing - always anti-clockwise.
- Try not to stay in one spot for more than a few seconds, the beauty of the dance is in constant movement. A single couple can ruin the whole flow.
- Overtaking is forbidden. If someone is blocking the flow though you can move around him going on the right. This way slow couples are gently shifted to the centre of the hall where they don't cause any collisions.
- No reversing, no 'blind-dancing', again it could cause collisions.
- Should a collision happen it's necessary to apologise. It's always the man who apologises as he is responsible for both.
- The man should protect his lady by turning her away from the aggressive couples. He is responsible for her feeling safe and enjoying the dance. Ladies must also contribute to safety by not swinging her legs behind her as her heels can be dangerous.
- Tanda. The music is usually played in sets of three to four numbers, separated by a brief burst of non-tango music called the cortina. Usually, dancers leave the floor during the cortina and change partners at the start of the next tanda.

Unfamiliar dancers should keep to these rules. Friends don't need to be so strict about the formalities but should still be considerate to other dancers and polite.