When you seek you beautify your home through the use of appealing wallpaper designs, let not your sense of naivete dictate the choices you make. There are many designs out there, far more than any one person is likely to be able to view and process, and you might lose sense of what would look good in reality when confronted with such a smorgasbord. Modern wallpaper designs may be contemporary, but remember that 'modern' changes as the years go by and become 'antiquated'. You want to get something that will outlive the current design trends of the day, unless you can afford the waste that changing wallpapers entails. Even if you can afford it, the environment cannot, so choose wisely and for longevity.
Be very careful of crazy wallpaper designs and funky wallpaper designs that may seem like a good fit for your home upon first impressions- you are likely to regret your choice once the novelty value wears off. The same goes for overly gaudy designs that may remind you of a more carefree period in history or your own life. Unless you truly like such designs, it's better to go for something more conservative and tasteful. That's not to say that some of the vintage wallpaper designs out there wouldn't work- gaudiness can be a virtue if done right. Unfortunately, it rarely is and it can be a challenge to find something that would work in your home.
Simple, solid colors can work great and create a more dramatic effect than many wallpapers. Red wallpaper designs are often used to create an energy in a room, but be careful not to overdo it as no one wants to feel "fiery" all the time, especially in a room meant for relaxing. Black and white wallpaper designs can be great for creating a sober, serious, or even stark environment. If that's the thrust of your personality, so be it. A more balanced use of black and white may be more subtle designs that lend elegance more than seriousness to a room.
Nowadays, it's possible to get mural wallpapers. Some of these will feature very pleasing designs that can be a centerpiece for a room. Because such wallpapers do tend to be rather visually dominating, you will want to be sure to pick something that you expect to keep for a very long time.
Of course, it's now also possible to create your own wallpaper designs to be made by a company that offers this service.