Growing up I played with watercolor a bit. It was not until 2 years ago I signed up for online watercolor classes that I discovered Daniel Smith watercolors. They are vibrant, glistening, and blend beautifully.
What I love about watercolor is its wildness--I can lead it in a certain direction, but water molecules go where they want to go. When I paint abstractly with them, it's like a conversation between me and the watercolor. "Oh, I see what you did there, how about this?" The spontaneity is delightful!
I also use one of my favorite supplies frequently: Neocolor and Sargent brand water soluble crayon. Many a scribble, dot and line are made with dipping them in water or running them on the rough canvas. It is pure play and intuitive freewheeling.
Other materials I use with watercolor include textile scraps, paint pens, watersoluble pencils, a variety of papers for collage, and stitching.