This free curled A4 paper mockup can really help you without putting too much effort when you have to display your stationery design, logo, typography, letterhead etc. Your presentation will come out in a realistic way. All you need to do is add your designs via smart objects. You can also change the background color, and the color of the paper as well.
Thanks to Graphic Burger for sharing this fine looking mockup with the community. Their website hosts a lot more, so check them out.