I don't have watercolor crayons, but do have watercolor pencils. I tried this technique on both watercolor paper (always on the left) and glossy card stock (always on the right). Thickly scribbled on blue in a zigzag pattern.
Used a water brush in a pouncing motion to liquefy the color and attempt to create the look of pointillism.
Scribbled on two shades of green, and repeated steps above.
Continued until the entire surface was done the same way.
Added some more colors and pounced the water brush over the surface to blend the colors.
Decided to go for a bit of glitz. Used the water brush to add some blue Twinkling H2Os.
Made two smaller samples, adding in some purple. Then added green Twinkling H2Os.
With the watercolor paper sample, I stamped a texture stamp with gold Encore ink over the smaller section. Used gold leafing pen to edge the pointillism pieces. Layered onto white linen card with small white piece. Added a metal seahorse. Stamped and embossed a saying in gold.