I have seen designers who did not use mock ups, instead, they export a jpg version of the design file and send to the client. Well, even if the design itself is good, it may not be a good idea, because the client may or may not have a great imagination and may end up rejecting a good design. So, it is always wise to put the design to a mock up to convey the idea better, and make sure your client see the design in action. This way, it will lower the change that your great design get rejected.
These mock up templates are all in 1600x1200px, 16bit multiple layers including, light, shadow, depth map, etc. And the most important thing is that they are all FREE !!!!
Note: On May 22, 2014, all the free items are only available for customers who spent at least 20 USD on the Standard Graphic store
Available for customers of
Second set now available here