Winter greeting cards can be simple. Here's a lovely one that would make great Christmas greetings for teachers. Or it doesn't even have to serve as a Christmas card, it could just be more of a thinking of you card.
Die cutting and gluing the trees on takes a bit more time, but once you get going it moves pretty quickly. I used my Grid Paper to mark along the bottom edge where to attach the trees, and then just repeated with each subsequent card. It made placement so quick