This morning I had a LD that was brought on by falling. This has happened to me before, such as if I’m on a roller coaster, falling down a tunnel in the road that has a very steep grade(last night), etc. I can become lucid without falling, but pretty much every time I fall in a dream, I become lucid.
Just for interest, the techniques I used were (in order): MILD, WILD(using the pencil writing counting method addressed in another thread), placing hands under your head(again, addressed in another thread), and apparently DILD.
So… in your ND, you was falling, which caused you to realise that you were dreaming.
So, for you, falling is a DS 
.
That, and bags of cookies. I kid you not.
I used to get falling sensations while i slept when i was younger, maybe this was a dreamsign i was unaware of?
Sometimes when I am very tired and I fall asleep quickly, I feel the falling sensations people experience with WILDs. Only since I’m not trying to WILD, I usually go, “Holy moly I’m falling!!!” 
, and wake up right then and there.
Anywhoo lehigh nagy, you can use your falling dreams as starting points for dream flight, which is always very fun.
I love the falling sensations! It must be why I love roller costers… 
Yay! 
My fav smilie!!!