hola,  how are you all doing today? this lovely template is by allisonsargent, which her edit is also pictured below. i gave a shot at making one myself, but holy wow her's is 1000x better *insert heart eyes*

Superimpose

i. Open the template below as the background and your first image as the foreground. 

ii. Put the image on screen under the transform tab and then move it as desired. You might need to use the rectangle masking tool to erase unwanted areas that go into other boxes. Merge and repeat until all boxes are filled.

iii. Open one of the images below as the foreground. Put it on screen under the transform tab and place it as desired. (you might want to use the soft brush to brush out areas on the face so it doesn't drown the image out) Merge and repeat until you're satisfied. 

Pics Art

i. Open the template and then go to add image. Add your first image and put it on screen on the drop down menu. Place as desired and press the checkmark. Repeat this until all spaces are filled.

ii. Open one of the images above and put it on screen. Place it as desired as well and then press the checkmark. Repeat until you're done. Save and add title.

feel free to experiment around with overlays; you don't have to just use these I provided you with (: