Respect your partners
Go to the dance freshly showered. Do not use strong after-shave, perfumes, shampoos, deodorants or oils. Many people are very sensitive - or allergic - to certain scents. Dancing close embrace Argentine Tango is an intimate connection. Make sure your breath is fresh. A mint to freshen up your breath is often a good idea.
If you perspire a lot during the dance, bring an extra shirt or use a towel to dry often.
If you are the follower and you wear glasses, consider removing them while dancing so they don’t bump your partner.
Respect the music
Tango is about intimacy and merging with the partner and the music. Dance mostly in silence and keep the talking to a minimum. Most people, if they feel inclined, use the time in between dances for a verbal exchange, but do not block the floor when the music begins for the next dance.
Navigation
When entering the floor, the lead should face the oncoming dancers or traffic and pick a gap to start the dance. Do not step blindly in front of another couple dancing with the leader’s back to the oncoming traffic. If you have the opportunity, make eye contact with the lead so he can acknowledge you and give you room to enter the dance floor.
In your dance, always follow the line-of-dance, counter-clockwise, around the dance floor in the outside lane. If there are many people dancing on the floor, there might be more than one lane. Pick your lane and wait for the time in between songs to change lanes.
Create ten-foot gaps between you and the dance couple in front of you and then dance into the open space in the lane. Try to not just spin in circles and hold up the dancers behind you. Create the gap, dance into it, and make turns and circles after you dance into the gap and at the corners.
As a leader, if you want to take a step back, rotate a bit so that your back is toward the center of the room. In that way you will not walk into the couple behind you. If you want to take several steps backward, rotate 180 degrees and move your back steps with the flow of the floor, counter-clockwise, making sure you know that space is empty.
If the couple in front of you slows down or stops in one place for a while, use a rock step, a giro or any other appropriate step to keep your dance in motion until they move, but do not pass them.
On a crowded dance floor avoid high boleos and other wide leg extensions that might not be safe for people dancing around you.
If you have just learned a new step and you would like to show it to your partner, try to do so in a corner of the room or in a low traffic area. Milongas are for fun and teaching on the floor should be reserved for tango Practicas.
Always be aware of other dancers' presence around you in order to avoid collisions. This is the leader's responsibility, primarily. However, on a crowded dance floor the follower can also help the leader to become aware of the presence of another couple using a hand squeeze, pressing her hand on the leader’s back or pulling closer to her partner. If a collision happens, try to soften it by using your arms and slow down momentum, and always acknowledge the other couple even if it was not your fault.
Respect each other
During the Cortina (the non-dance music interlude between Tandas or set of 3 to 4 songs) if you are the leader, accompany your partner off the floor before you invite another partner to dance.
Although the Cortina is the customary partner-changing opportunity, it is acceptable to leave the floor before the end of the Tanda if you are sufficiently uncomfortable with your partner's dancing or other behavior. Saying "thank you" to your partner is a coded way of saying, "I am done” or “I want to stop dancing." Use other expressions of gratitude if you want to keep dancing. For example, “that was delightful” or “let’s do another tanda”.
Tangueros love the music. Loud or long conversations on the floor are not well received.
If you are a more experienced dancer, it is OK to give feedback to your partner only if they asked you or you have first asked their permission to make an observation. Be sensitive toward your partners, as the nature of Tango often places people in a very open and vulnerable position. Generally a Milonga is not a place to give ANY feedback unless asked (compliments are OK!). The Practica is the place to give feedback.