Here's a simple but useful technique for framing:
1. Make a new document in any size you want.
Use the resolution that you normally use for layouts
2. Make a new layer, name it Slide.
3. Change the foreground color to a light gray.
4. In the tools menu, choose the Rounded Rectangle.
5. Up in the Option Bar, click on the third icon from the left, “Fill Pixels”
And change the Radius option to .2 in
6. Hold the Shift key and drag the Rounded rectangle tool to form the square shape of a photo slide.
7. Turn the layer into a Smart Object: Layer/create smart object
8. With the regular rectangle marquee tool, draw a square inside the middle of the gray rectangle image
9. Reverse the selection: Select/Inverse
10. Click on the layer mask icon at the bottom of the layer’s palette.
You should see a black square in the mask and a hole in the rectangle
11. Add a Drop Shadow.
Use the settings that look good to you.
Optional: You may add some texture without losing any original data since this layer is a Smart Object. Filter/Texture
12. Grab the text tool and with the Times New Roman font and black color, create some text at the top and bottom of the slide.
13. Change the opacity of the text layer to 50%.
14. Pick a photo to use as the color slide and place it under the Slide layer.
15. Transform or trim the photo to fit inside the slide opening.
And there you have it!
Remember to save this file to use as a template. Use again and again with other photos for your own "Slide Show"