This one in particular turned out above and beyond what I pictured it to be!
At first, it was just going to be the cellist with a blank background. It didn't look festive enough (especially since the guy is wearing almost all black ). So, I painted some snow but then, it looked incomplete without any snow in the background. I couldn't add white over white for obvious reasons so I added the background. The color scheme of that background was somewhat inspired by 'Tegami Bachi'. In the end, it turned out very well and I can say that, by experimenting a bit, I grew as an artist.
Here are the other three cards I made...