Here's how you do it.
To start off, every single day, when you wake up, immediately write WHATEVER you remember from your dream, however little, on a notepad next to your bed.
You'll start to notice within a few days that you now remember MUCH more of your dreams, because by writing what you remember down, you're training your brain to think that your dreams are important and must be remembered.
Now, the entire point of this is to make your brain realize it's a dream, so that you can control it.
There are many things that you can do for the next and main step. Whenever something "amazing" or unusual happens in your life (Real life), do one of these:
1) Look at your hands to "make sure" they're real. In a dream, your hands will look frighteningly did informed and mutated out of shape. In real life, they're just... You're hands.
2) Check your watch. Both reading books and clock time is used by a separate part of your brain that is not used when dreaming. By a book, the words will be impossible to read, and by a watch (analog; I don't know about digital), the hands will move frantically about, and change by any amount of hours in a second.
3) Check a mirror. You will not be in the mirror. You will have no reflection.
4) Turn on/off a light. The reaction to switching the switch should be delayed, or might not happen. Be careful, though. You're dreams will easily turn into nightmares if the light switch doesn't turn on. Believe me.
5) That's all that I know, I think.
This is also repetition, so I guess Para's way would also work.
I recommend using your hands, as they're the most available to you.
The point of this is that: You constantly do any of those things in real life whenever something unusual happens to you. Then, one day when you're dreaming, (on average two weeks of doing that) you do it in a dream. Then, by doing that, you immediately realize it's a dream, and you can control it. Keep in mind, though: At first you won't be able to control your dreams. As you realize that it's a dream, your brain will try to wake you up and kick you out of the dream. It's recommend to do something repetitiously, such as running in circles, as it's an easy way of keeping your concentration on the dream. Over time it'll become natural, and you can control your dream.
Pros: Do I even need to say this? It's ******* amazing! If you're the dirty type, have fun. Just know that you're technically ******* your brain.
One thing you may want to try is: Go around to people in your dream and tell them that they're fake. Supposedly the results are hilarious! They curse you out, attack you, etc. they don't even know that they're fake.
Fly! It'll be exhilarating!
Cons: There are two of them, and a potential third that I don't know whether it's true or not.
1) Sometimes your dreams will end abruptly, before your body has time to wake itself up. What'll happen is that you'll wake up. The problem is that you're paralyzed for three minutes or so before your body itself wakes up.
Here's what happens: You'll be awake, but paralyzed. Sounds fun? No. Your dreams will still be happening, but in real life, where you can actually see it with your eyes.. It's terrifying, from what I've heard. You'll hear terrifying sounds. Screaming, or anything like that. Also, you'll have ******* monsters from your dreams climbing on the ceiling an staring down at you. Basically, your dream will still be happening around you, but only to you. If you get depressed or scared easily, watch out.
2) Your dreams are a way for your brain to express itself and review what happened throughout your day, and review the small details that you missed, all in your subconsciousness. So, technically, you're robbing your brain of something that could very well be essential.
3) I don't know about this, but I've heard it once before. Supposedly his lucid dreams lasted for around 40 minutes until he automatically woke up. Basically, he couldn't sleep more than 40 minutes at a time, because he always, for some reason, woke up after a 40 minute dream.
Wow. That took a while to write. I've never been able to lucid dream, but I think I'm going to try again now.
I read this somewhere, and I'm rewriting it for you. I think it took 25 minutes, or so.