Here's how I have lucid dreams, take it fwiw, and I don't them every night (more on that later):
You have to concentrate on your daily routine a lot. For example, as I sit here typing this, I can read the letters, and I can read everything I'm writing. This is all very vivid, and "real," (obviously). But, I question it, constantly (if I want to have lucid dreams) because you have to get used to actually questioning things enough to do it in your dream.
It's a habit, and you have to gain the habit, and it can be exhausting, and it's an easy to lose habit. I'm typing. Is this real? I'm looking at a computer screen that's very detailed with words, is this real?
Eventually, you can ask this question in a dream. And, once you ask it, and figure out that it's not real, you realize you're in a dream, and you can do whatever you want.
Don't worry, normal dreams still allow for this. But, the more weird the dream, the easier (in my opinion) it is to eventually get to a lucid dream.
Also, while in the dream, never worry about it lasting. When you wake up from it, try to appreciate the even five seconds you've had. The more you appreciate what you experience, I personally think the longer they eventually happen.
I don't have them every night, as I said earlier, because I don't concentrate on it daily. It's more like a "want" that I remind myself of occasionally, and eventually revisit from time to time. It takes time to build up to having them, and you have to constantly keep up with the mental exercises of questioning if this is real, or not, etc.