Here is an easy peasy card because it is easy to make your colors go where you want them to. Yes, this was no accident. hehehe If your paper is dry, your watercolors won't run out of control as much as a wet on wet technique. Just a tip. As Susn says, "it is easier to contain the color where you put it". You put your wet media (watercolors blue and green) on the paper and tilt the paper so you get the drips and runs where you want them. Now I wanted purple after I had the blue and green on, so that's what I did. I added the purple, tilted the card and let it run. I really liked the addition of a third color. Let it dry and then stamp a large stamp to give it some cohesion. A ribbon here added some interest.
I didn't get the image stamped well here, but if I didn't tell you, you wouldn't have known it. The happenstance of art!
I really do like the way this turned out.