The principle of a rebound is that you lead a direction, then change your mind, either half way, or right at the end, in order to come back. Of course, you never "change your mind", you plan it all along and let your partner know about it in good time. How you do that? Simple. You lead the first direction, but as soon as your partner gets it, you lead the opposite. That way, by the time she gets to the first half of the beat, she already knows where you need her to be next.
Now, suppose you want to push this further - go one direction, then back, then change your mind again. Since the direction at the start of the movement is the same as at the end of the movement, there is no point leading the opposite direction at all, because nobody is going there. If you're in a car and you lead the backward direction, but in the end still go forward, how do you call that? A break! That's what you do here, also: you break the movement.
And you can break it more than once, during one movement. The point is that, while you release the break, you need to show your partner what comes next: another break, or a continuation. You do that in a variety of ways, two being the most notable in my humble opinion:
1. the freedom you give your partner to release the energy from the break and
2. the counter-position: you achieve the break with a counter-position, but the release is also a counter-position. The acceleration pedal is a force inflicted on the car, just as the break pedal - except you usually decide to follow-up on the acceleration pedal; however, if you decide not to, to push the two pedals alternately, you achieve a series of counter-positions which are quite clear to your partner. Something like the ABS.
But let's take the trick up a notch: reach an "American" position, then lead your partner a gancho to your forward leg and try to keep her there for a second, chained, gancho; then lead her an exit to a back ocho. ;)

That's part of the beauty of being a leader, in fact. The follower lives in a blissful ignorance of the leader's plan, and on top of that, she often has plans of her own - in her own, soft yet compelling manner.
Think of it this way. You are a married, mad scientist - and one Friday morning, with dark passion thundering in your eyes, you tell your wife: "Today, I shall take over the world!!" And she replies serenely - "Certainly, dear, but first you have to walk Schmuffles; and pick up some milk on the way, will you?..."
Personally, I think it's her hand on your back which does the trick. But no matter: the point is this - each and every step you take as a leader, each plan, each dynamic needs to depend strictly on the follower's response. It's a waste and a shame when you do a splendid back sacada with double voleo, followed by two baridas on a gyro - and in the meanwhile your follower watches amused from a safe 5 feet distance, because you lost her after the second step (when she decided to do a long, passionate caresso).
You do good, as a leader, if your follower is comfortable. And mind you, that alone is a tough game of the mind. If you are lucky enough though to have a constant tango partner, then you can reduce the hard riddle to a simple matter of communication. Naturally, there is nothing simple in that either - unless you remember what I just wrote in my title.

Tango is a social phenomenon. The ladies get to walk their new dresses around fancy parties available all week long, the gentlemen get to show off slick moves or silk embraces, there's talk, there's tension and there's feeling.
Now, where you've got society, you've got civilization - and with it a number of rules. Since the dance itself doesn't have too many rules, most of them refer to the relationship with the others, and therefore they apply to the couple rather than its parts. Since the couple itself is asymmetrical as far as responsibility goes, if it messes up, it's the leader's fault. Just like it's the driver's fault when a car crashes.
And the resemblance doesn't stop here.

1. The leader, much like the driver, has a number of tools with which to steer, accelerate or break. Each different car steers, accelerates and breaks in a slightly different manner, and you need to get accustomed to these peculiarities, in order to drive safely.By now, the ladies have probably sneered, understanding that they are being compared to cars. In my own defense, I honestly believe that most cars are smarter then their drivers, at least in what driving is concerned.
2. You drive on the right side of the road. On your right, you should always have the landscape. (In tango, this is true also for the UK).
3. There's traffic. It cannot be avoided. Still, if you are usually more careful not to scratch your car than you are not to lead your lady into a crash, then you should feel bad for a whole minute right now!
4. More crowded traffic doesn't mean a chance for more people to see how great a driver you are. It just limits your freedom to maneuver. Often, it tests your patience.
5. It's more crowded on Friday evening. 
6. There's more than one way to drive a car - and there is a number of conditions which will commonly influence your choice - such as the traffic, the lighting, the driving surface, how tired you are, how much you like your car and how comfortable driving it is, or the music you listen to. Selectively and arguably, all these apply to tango as well.
7. When you reverse, things tend to come at you from behind. So, make sure they aren't close enough to hit you.

The second installment in our series of beginner's tips for leaders. Here goes:

1. Keep your shoulders on a horizontal line - don't swing during the dance (that means sideways as well as up/down). Just imagine your follower is trying to read the fine print on your T-shirt. Or - have you seen those Indian ladies carrying tea pots on their heads? That.
2. The order of things is: intention -> follower's step -> leader's step. Even though these all usually happen within half a second, you need to think of them in this order, because your reflex should not be to just walk and make your follower walk, but to make your follower walk, check if he or she did, then walk.
3. When you step forward (and you will be doing a lot of that), make sure your head, your chest and the tip of your foot are on the same vertical front. If your head goes ahead, you lean forward and we already agreed you wouldn't do that; if your foot goes first, that means your follower didn't get the intention yet, has no reason to move and you will step on her toes; if your chest goes first, you'll look like a chicken. The "vertical front" movement is the safest way to ensure that your step will fall under your body, where there's no way you might find the follower's toes.
4. Think at half tempo level. If you feel the tempo beat comes too fast and you have no time to perform your tricks, "overclock" your plan! - think in terms of half tempo, and the tempo will seem like all the time in the world
5. Think at double tempo level. It's harder to do a trick slowly, but it helps a lot. It improves your balance and your leading skills and it forces you to manage the energy better.
6. Do not abuse on the "ochos". They put an unnecessary strain on your follower and they are not a remarkable achievement by themselves. That means, at the end of two successive "ochos" there had better be a stunning trick in your plan, otherwise your follower is entitled to give you a black eye.
7. Do not abuse on the sidesteps either. You know that not very meaningful Tango trick called "standing still"? Well, sidesteps are even less meaningful. So, when in an inspiration crisis, stand still, embrace your follower fondly, make a dreamy face and wait for the next phrase to begin.
8. What you lead to the follower and what you do yourself are two different things which sometimes coincide (for symmetry). You should be able to lead any step (forward/backward/side) to your follower, while performing any of those steps or standing still - all as long as the embrace doesn't break.
9. As far as balance is concerned, you need to mind your own axis and the follower's axis, or rather her or his space. When you invade this space, the follower is in danger of losing balance and thus so are you.
10. Tango music is usually composed of 8 tempo phrases. It is nice not to tap around while a phrase ends and another begins - and it is also nice to stop walking when the music ends. Exactly when the music ends, that is. It is also nice to make a dramatic pose - exactly when the music ends.
11. Don't learn steps. Learn how to lead steps. Whenever you learn a new step or trick, practice it in various sequences, try to start it in different ways and continue it differently. Many times you will learn exercises. Don't just repeat the exercise. As soon as you get the hang of it, vary it. This will also help your followers a lot.

Here are some useful notes for a beginner leader:

1. Step straight forward in full confidence - or you will just end up doing a funny swing, thinking to avoid her feet. Now, stepping on her toes might hurt your dancing relationship, but walking like a duck will definitely kill it. Put your heel down first, and not the way you would if you wanted to kill a bug.
2. When you lead a pivot to your follower, have in mind what comes next and make sure you share that thought. A pivot is much easier if it takes the energy from the previous move
3. Keep a straight pose. Do not seek to help your follower in his or her job by bending inside their space. You will achieve the exact opposite and the couple will look dreadfully.
4. If you do want to help your follower, concentrate on keeping the information flowing in all possible sources: your arms, your upper body, your hips. If your follower can understand what you want, without being a psychic, that makes him or her comfortable
5. Your attention should be shared between your own dance plan, checking if the follower is where you expect him or her to be and checking the environment (i.e. the other pairs, the space, if the wife is looking, etc.). The first factor is up to you. Try to minimize the second and maximize the third.
6. If your follower ends up on the wrong foot (in reference to your dance plan), you have two solutions: - adapt; or -stop. It's OK to pause, adjust your embrace, reset the steps and then start again. Don't pause if you can adapt, but pause, rather than require your follower to adapt.
7. Be firm in your decision, don't hesitate. Make your steps clear and decisive, even if they are wrong. For a follower, being unable to follow what you lead is far better than not knowing what you lead. Partly because the former situation rarely ever happens. Followers are quite resourceful.
8. Never be afraid to ask someone to dance. When you ask, though, be honest about your skills and stick to what can't go wrong - particularly if you have never danced with that person before.