For one of my classes at Wesley (Digital Illustration) we had to design a Christmas card for a company that we created in class. Aside from the fact that the entire thing had to be a vector and a scene, we had complete freedom in our design. I created a scene with an oak tree covered in decorations with two deer standing under a mistletoe. The inside of the card simply had a unique christmas ornament, the company logo, and the greeting.
The entire project was created in Adobe Illustrator and was created entirely with the shape, pen, and type tools.
I do enjoy these kinds of projects. Illustrator is the program I am most familiar with and I tend to have little trouble when making these types of illustrations. Though the tree and the deer took a considerable amount of time compared to everything else.