Corrosive Challenges the theme is masking. You can mask your images and create a scene, as I've done, or you can mask off areas of your card and create a frame. I've used Hobbyart Scene-It stamps and both snowman and tree were masked when I stamped the houses and the tree. I've used Aquamarkers and Marvy le Plume watercolour pens on watercolour cardstock, I've also added a bit of glitter to my snow and to the snowflake embossed card.
I'm entering my card for these challenges:
One Stop Craft Challenge - snowflakes in September
Totally Gorjuss - Christmas
ABC Christmas - T is for Tree