Presentation is everything. Whether you are showing your design to a client, featuring it in a website, or even showing it in your own portfolio, you need to present it the right way. A great and an effective way to present your design is to use mock-ups.
For those of you who don't know how to use photoshop mockups, it's very simple. Once you open the mockup in Photoshop, there is always a smart layer that you can double click. That will take you to another tab to place your design in. Once you're done, save and close and go back to the original tab to see your design in effect. That it is really it! Simple and very effective!
Here are some free mock-ups you can start with.