Here's something I did at my late grandmother's cottage on a man-made lake. It was during a family gathering. This was the view of the lake from the picnic table in the back yard.
Kept having relatives telling me to move my laptop...
I knew I wouldn't have much time to do color, so I kept it black and white. It was a pretty quick one. I'd say 25 mins. Part of it is my imagination. I started it earlier, then finished it when it was almost dark, so, being without well-lit reference, I BS'd in some of the trees on the right to make it look a little more grand and epic.
Actually, come to think of it, it doesn't really look much like a lake. More like a field. Perhaps I should finish it and add some reflections... nah.