There are some people who can start a lucid dream intentionally. I am not one of them. They happen more or less randomly. The key for me is: As soon I realize that I am dreaming I can take over. There are many tricks and techniques that help you to regognize that you are dreaming while you are dreaming. I have found out that I am not able to count backwards while I am dreaming. In my reality I count down from five to zero about 10 times a day. In silence of course. When I am dreaming it happens from time to time that my subconscious is counting backwards from five to zero because I am doing this in my real life. Because I am not able to count back while dreaming I fail to do so and then I am becoming aware about the fact that I am dreaming. This works for me. I think one of the best resources is Google in this matter. You have to try a lot of things.

One technique to get into lucid dreaming is to try to look at the palms of your hands or to try to look into a mirror while you are dreaming. This will bring you to semi-consciousness or lucid state and will put you in control of your dream.

Check this website out. It has a lot of information:

http://www.lucidipedia.com/

Thank you, that site is very interesting!

A decent hypnotherapist can kick-start one. You can visit past lives, future lives, and in-between lives too.