Prepairing for Autumn Equinox

I have been designing the advertising poster for Arctic Circle of Anchorage's Autumn Equinox Celebration and thought I'd share my process:
Started with notes and sketch & then Finished sketch

Then contemplated which direction to go with it. For a poster I decided to go with what I call "Illustration style"
I transferred the image to a 2ply cotton paper and added watercolor. I think next time I will just start the sketch on the paper.

The finished Image

The first draft of the poster: