1. You cannot expect to use them like watercolor. Big broad loose juicy watercolor strokes did not work for me. When I used a very wet or sort of wet paint brush I moved the color around but the pencil mark remained. I didn't like that look. My brush had to be slightly wetter than damp. (Does that even make sense?)
2. It is better to layer colors and then wet the pigment to blend. I tried putting on one color, wetting, layering on another color, wetting, etc. Didn't like that.
3. I had to think of them as colored pencils and not watercolor. It is about mark making not about painting. It is a somewhat slow process.
4. A smaller brush worked better for me. I learned to use it like the pencils, watching my strokes and contours. When I teach painting to my students, I always encourage them to be painterly and not to draw with their brush. With this medium I felt like I was drawing with my brush. But that is okay. It worked.
5. Just like painting, some of the pencil colors were more intense than others. You have to experiment with these colors for blending.
6. It is difficult to lift color. I didn't try an eraser or an electric eraser.
7. I liked smoother paper more than textured. I had more success with a drawing paper than with a watercolor paper.
8. The watercolor pencils would be nice for sketching on locations. I used a small (#2 round watercolor brush), but a small waterbrush would work well too.
Here is my quick little practice painting from a photo I took many years ago: