I started with a watercoloured piece of cardstock and applied Paperartsy Grungepaste, which is a claylike modelling paste. Mine is quite dry, so I didn't have to wait, just sprayed some water on my stamps and pressed them in the paste.
I added colour with sprays, watered down acrylics, Derwent artbars and white embossing powder... and some details using the other stamps from the Art Journey tulip set. While I had the stamps out, I used Distress inks and spritzes of water to stamp the images on the envelope. Love a bit of mail art when I get the chance!