]I am no expert but do have a lot of experiences with lucid dreaming.
And I agree with beauflow, these are the definition of a lucid dreamer.
I can not wish for a certain dream and fall asleep into dreamland.
When in a dream state there are always signs to tell you, this is a dream.

For example if you are dreaming that you are in France and you know you have never been been there, you should recognize you are dreaming.

For me i have a recurring dream that I am on a cruise and I have never been on a cruise so I am aware of the dream then there comes a time where a crew member comes to me and says "we are leaving, are you ready to go"? I want to stay but I know its not my time, and I dive into the ocean. (the other clues are I can't swim and would never dive for fear of heights).

In the beginning it takes a lot of practice of awareness and self control. To be non reactive and watching what comes to me how I am acting out in the dream and the emotional states involved.
This is my subconscious at work.
Happiedasiy