Everyone needs a file system. However files that need to be used frequently can live on your desk in something like this. I like that it's flat rather than graduated and has side enclosures. Keep those papers safely tucked in one spot!
Keep decorations subtle like these pictures, but avoid overcrowding your desk with personal products - 20 Creative DIY Cubicle Decorating Ideas, http://hative.com/creative-diy-cubicle-decorating-ideas/,