Hi, I have experienced lucid dreaming many times and from my experience it is triggered by being more aware of yourself during the day.
If you practice not being overcome by your inattentiveness and lack of awereness during the day, it will be easier for you to control the dream. As I see it, the more are you in control during the day the more you cand be in control during the night (by being in control I don't mean repressing or forcing anything).
What it changes - well, it makes things more interesting and you get to see a beauty you wouldn't normally have access to. In my particular case, it puts me in touch with my deepest fears.
Speaking of fears, I haven't managed to get through them in dreams until recently (I suppose that's what it was).
In one of the recent lucid dreams, I was locked in a basement with creatures who told me I'd better stay there because it's pointless to fight them (this looks a lot like my thoughts lately), but I fought them with a katana sword and I won and managed to get out through a door.
I climbed some stairs, I passed a river in a boat (like the river Styx surrounding hell I thought) and I knew I had to get to the sea ("to see the Sun rising from the water"!). The creatures were still following me and telling me it was pointless but I didn't care.
So for the first time in a lucid dream (I usually dreamed I remained stuck in that room) I got where I wanted and it was easy! And I saw the Sun rising from water and I knew that "for the next five days I must stay there because the most interesting fish will come and tell me stories"!
I thought maybe this has to do with my Moon in Pisces who is in the 12th and with the Sun's energy that wants to be freed.
Nothing happened in the next days, but it felt good to win for once!
In my last lucid dream, I ran through a field with beautiful flowers and leaves who grew directly from the ground (! - some "real world" rules are not respected in dreams) and when I looked back I saw an extremely dark storm approaching. I said to myself - Well, that's it - and I climbed on the roof of a house to see it better. As it approached I did nothing to stop it, I just stood there and the storm came right through me. I felt spinning faster and faster, I saw a lightning and I heard a thunder and I woke up. But, more important , I wasn't afraid!
After that, nothing happened
So I use lucid dreaming to get through my fears. And I only do this since two dreams because before that I just experienced them.
If it weren't for the "darkness" that bugs me during the dreams I would definitely do it for the beauty. It is different from the one you usually see, more powerful and very special. And I noticed after a lucid dream I get more sensitive to the beauty I see when I don't dream. So maybe it's there all the time but I'm not always able to see it!
So lucid dreaming transforms me more into a courageous person and into an artist.