Make a pattered image like a brick wall look like text is popping out of it.
Instead of popping out, you can make the text look like it's going inside the wall by by making the shadow thicker on top than on bottom.
Perspective Clone Tool will allow you to clone part of an image into the foreground or background. It does this by scaling the area at the same time that you are cloning it.
Add text to a photo in a way that makes it look like it's behind other objects in the scenery.
A demonstration of creating a color wheel diagram, first of cyan, magenta, and yellow- then again of blue, red, and green.
Create a "connect the dots" or "rhinestone" pattern using Scatter effect (rather than Pattern Along Path).
Combine pictures together to put eyes on your hands.
Make characters look like they are sticking out of the picture frame.
Use an overlay texture to create zombie skin in your images.