Every month, on ATCs for All there's an ATC contest. In September I entered, the theme was "Hidden beneath the layers" and won! Woo hoo! Very exciting for me - and apparently there's a little package of goodies in the post on its way.
I used mixed media: watercolours, ink, gellyrollers, metallic pastels, silver pen and watercolour pencil crayons - I tried to build up various layers and a sense of depth using the different mediums.
My card is featured on the front page of the site (you have to scroll down to the bottom).