Places, where this A4 paper mockup can really help you without putting too much effort, is when you have to display your stationery design, logo, typography, and letterhead. Your presentation will come out in a realistic way. It features a clipboard with 2 a4 letterheads. All you need to do is add your designs via smart objects. You can also change the background color, paper, and clipboard colors.
Thanks to Graphic Burger for this interesting mockup. By all means, check out their website for more awesome freebies. Subscribe to them to be updated as they roll out new resources as well.