Envelopes, patterned papers, glitter papers, and Christmas collage images from Altered Pages. I used the Holiday Postcards, Christmas Minibook, and Santa Santa Santa--there are tons more to choose from, and not just in traditional red and greens.
For all the collage images you need, plus the numbers, you can download the Altered Pages kit HERE. Just add your own envelopes, grab a gluestick, and have at it!