First stamp an image using white pigment ink and allow it to dry completely. It's best if you use a stamp that has a good amount of solid area to color. I also like this technique on a dark background, although it will work on any color.
Next, using chalk, or colored pencils, color in the white areas. You may wish to leave some of the colors white for contrast.
That's all there is to it! Simple, huh? But so effective! Below are two cards I finished up using this technique.
I tried spraying the bottom one with Smooch Spritz. I should have just sprayed the bottom layer and not the top piece - it looked a little too messy for me. Anyway - it's all about playing with your tools and learning what works and what doesn't - BE BRAVE!!