Leading and following are the two most important things in any type of partner-dancing.  You have a leader and a follower.  There are a lot of aspects to consider in becoming a good leader or follower.  While there are too many to cover in this article, we'll just focus on the main ones.

The leader role is more complex and difficult.  There are three main fields that a good leader should cover while dancing with his partner.  They are leading, timing and safety.

Leading: The leader is responsible for creating, improvising and executing moves to keep the dance interesting, while at the same time allowing the follower enough freedom to express her interpretation of the music.  He should execute moves that match the music and adapt his lead to the level of his partner (for example, by adjusting arm tension or by making the lead less or more obvious).  You should never try to execute the same moves you lead on an advance dancer with a beginner.  Also, a count before you start any move you always have to signal it first so that your partner is aware that a move is coming right after.  In order to develop a good lead, you should have a steady, close, open, firm and subtle grip.  Your palms are probably the most sensitive part of your body.  Use that sensation to communicate what you want her to do.  If you want your lead to be easier to follow, lead as if your partner is blind.

Timing: It is the leader's responsibility to keep both himself and his partner on time during a whole song.  This applies to whatever beat you are dancing on.   For instance, if you started dancing a song On1, stay on the 1; if you started to dance on the 2, stay on the 2.  Do not change the timing in the middle of the song or a turn pattern.  The timing starts with the music and goes to your feet.  If you change the timing in the middle of a turn pattern, for example, and you whip the girl to step back when she was about to step forward on her basic, you might injure her.  Stay on beat the whole time.  Do not expect the follower to keep you on the beat.  It's like going to work and expecting others to do it for you.  If you want your timing to improve, dance as if your partner is deaf.

Safety: It is your duty to ensure that your partner is safe at all times.  No one likes those selfish dancers that you find at the clubs that use the entire dance floor with no regard for others.  Just as bad are the ones that push people around or bump into you demanding more space.  The funny thing is that really good dancers don't need to demand space.  It is always the not-so-good dancers that do these things.  Keep your partner safe.  On a crowed dance floor don't try big extensions that cause her to end up between other couples.  Don't dip her into someone's knees.  DO NOT try to flip her, or do any other crazy stunts that would cause her to end up on top of some guy.  Leave the stunts for performances.

The follower's job is simply to follow, but it doesn't stop there.  "The man is the frame and the lady is the picture", so in order for the leader to look good, the follower needs to look better.  The three main things the lady should be aware of while dancing is arm tension, following the hand and styling.

Arm Tension: Arm tension is something really important while following.  When you are a beginner, your tension may be either too soft (i.e. spaghetti arms) or too stiff.  You need an arm tension that falls right in the middle.  Do not expect the guy to carry your entire weight.  Rather, share it with him.  If you are wondering how your arm tension is, pay attention to your arm while executing an extension.  Is it locked all the way?  Is my shoulder moving forward?  Is my back straight?  Once you get the correct arm tension, you'll be surprised how much easier it is to follow ins and outs, and you will notice that you can fit more turns in a spin.

Follow The Hand: Notice that guys are always leading with their hands.  When they have both hands there is always one predominant hand that is the one you'll need to follow.  If they have just one hand, it's easier to know which hand you should be paying attention to.  If, however, he is trying to ask for the other hand 99.99% of the time, he is going to show you the palm of his free hand.  This means "I want your other hand here."  Pay attention on what kind of grips he is using to hold your hand.  You can almost guess which direction you are going just by the way he is holding your hand, but make sure that you are not assuming and lead yourself into moves.  Always wait for the lead.

Styling: Notice that I put styling last.  Following always comes first.  Styling is secondary.  Once you are on an intermediate level, you may fall into either the "no style" or the "over style" category.  The second one is the more difficult to get out of.  You should start experimenting with styling movements while partner-dancing after you have developed a higher sensitivity and a quicker response to different leads.  Your styling should not interfere with the lead or the following part of the dance.  The best time to style (or the easiest move to style to) while partnering dancing is when stepping back on an extension.  A great way to develop your styling is to learn shines.

Whether you are leading or following, the main purpose of the dance is to have fun.  Mambo/Salsa, by its very nature, is a social dance, not a competition or show (even though there are competitions and performances).  While you are out there dancing remember that no one is perfect.  Don't correct others or make any funny or nasty faces if something doesn't work out.  We were all beginners at one point.  Always be considerate toward the one you are dancing with.  The one you are criticizing now may someday become far better than you.  Considering these helpful hints will help you pinpoint the areas that you need to work on.  The only way to improve is by practicing, so go on to the dance floor and have fun, and remember practice, practice, practice.