In the billboard mockup I, I added the photo by selecting the inside of the billboard and copying and placing the image in the selection.  In Photoshop Elements, I couldn't figure out how to do this automatically the way you were showing but it worked out.

I made a mockup with my logo on a coffee cup. I couldn't find the warp in Photoshop Elements so I used a distort sphere instead.  I learned a lot about using the blur and the dodge shadowing and highlighting.

Thank you so much for this class - I will definitely be using these techniques!