Another lucid dream and a few questions.

So this is my second lucid dream, I had my first a few days ago. The dream started off me not being lucid. I have two little sisters, Indie (9) and Zella (7). It basically ended out we were in a small barn screaming for help because there were giant beasts and monsters trying to get in and kill us. At that point I realised I was dreaming. I didn't do a reality check like I did in my last dream, I just realised. I instantly grabbed my sisters and flew out of the barn and over the paddocks and the lake. Than I asked them if they could fly themselves home and they said yes, so I went down to the lake. I felt myself starting to wake up so I focused on the view, and the ripples the kayaks made in the lake and the colours of the sunset. Once I was sure I was stable I decided to try and transport myself back to mums house. I closed my eyes and imagined I was standing in my mums drive, and when I opened my dream eyes I was there. I went inside to make sure my sisters were ok before I woke up.

How did I just become lucid? I didn't even do a reality check or mantra or anything.
I think the thing I did was visualisation, is it?
And how do you make your dreams last longer? I always wake up before I start to do fun stuff!

1. The DILD method. Sometimes awareness just comes to you apropos of nothing.
2. yes and well done. I'm unable to do that currently.
3. Stabilize and try and ignore your physical body, whilst keeping awareness that you're in a dream. Another method would be to try and slow down time in the dream. One way you could do this is to conjure up an analogue clock and force the ticking to slow down, whilst keeping yourself at normal speed. I'd focus on mastering the former first.