Don't worry too much about the dimensions. I simply started with the scalloped square, then figured out what size the patterned paper would work as. In this case, I used the largest square nestability, and the squares end up measuring 1-3/8 with the mat.
When I went to place the sentiment, I realized that neither white craft ink or chocolate ink would show up well over the patterned paper. I tried a slightly different approach. I stamped the greeting on a piece of Spring Moss, stamped a snowflake on some vanilla cardstock, punched that out, and pieced it together nicely over the square. I like how that turned out.
One fun thing about this sketch is you can really make it as simple or complex as you want. It was somewhat inspired by last year's Fall/Winter Stampin' catalog cover. That one is an example of just how complex this layout can be. My card, however, is an example of this layout at it's simplest. Feel free to add in a square layer behind the 4 squares, use more than one type of patterned paper, add more embellishments, have fun with it!
Supplies: Stamps: Snow Flurries, Mixed Messages
Ink: Chocolate Chip, Cranberry Crisp
Paper: Cranberry Crisp, True Thyme, Holiday Thyme DSP, Vanilla
Accessories, etc.: 3/4 circle punch, various nestabilities, pop dot



