Negative space, masking fluid and white over watercolor:

 

A dubious "hack" because I didn't want to wait to get the right flat and round brush: Cutting the bristles of a flat brush I already had: 

 

Clouds activity:

 

Final project:

I am both proud of this and can see lots of room for improvement. For textures, I used alcohol on the moon, salt on the sky, and mixed some glitter glue into the paint for the dragon. I used masking fluid on the moon, mountain peaks and dragon. And white over watercolor for stars and clouds.