There are many ways to customize your desktop. The easiest probably being the wallpaper. There are so many wallpapers and images available online, you just need to search for them. Once you find the right one, right click it and set as background. (Some wallpapers work better than other depending on the size of your screen).
Finding things on a desktop that is organized is much easier than a desktop with cluttered icons in no particular order. Organizing your icons are easier, just drag and drop.
Right click the start bar and select properties. Go to start menu and select customize. In this section there are many things you can do to make your desktop look like your own from colors to images to fonts.
There is also a wide variety of software available that allows you to add things to your desktop that you would normally not be able too and also apply a lot of cool effects.