I believe that you can tell a lot about how someone lives their life by judging how they choose to decorate their Christmas tree. If they go for something classy and minimalist, they're probably quite image conscious; tacky and laden with tinsel, they're the sentimental, traditionalist type. Those that put up several joke decorations believe in not taking life too seriously, and if they have no tree at all, they're an obvious Scrooge (so long as they're not a part of the vast population who don't celebrate Christian holidays).
Personally, I don't see the point in trying to be tasteful with tree decoration. Bright colors and too many fairy lights are just a lot more fun. They also give us better material for memes. As we know, this should be the most important factor when choosing how to give our home some festive cheer. If you come from a Christmas-celebrating household, you should be able to relate to at least some of the examples below.