I think that I sorta learned to have ongoing dreams (LDs). When I was little I had dreams which continued on and on. but those were dreams I could never change.
Well,several years ago I've been playing video games a lot and I also got stuck a lot. At night I usually went to the place in the game and I tried to figure out what I could do and usually it worked in the game itself (I tested the day after).
Well, with this I started to "load" settings and the actual "problem" and it taught me how to resume dreams.
At first I've been really "saving" a dream like a game in some engine. I just imagined that I saved the dream in some file. when I wanted to continue I induced myself a lucid dream starting with this saving sequence.

Now I just induce my LD with last scene of the dream I want and it works.