Must start from a face photo taken from the front ... of course! If you want to work with the photo of Britney Spears use in this tutorial, you can download it HERE
Open the photo in Photoshop (or any other image editor).
It takes place to work ...
Also, do : Image> Canvas Size (Alt + Ctrl + C) and triple the width of the image ... without changing the it height ...
You will now get the first half of the face. With the rectangular marquee tool select the 1st right part of the face (compared to Britney ...)
ou can move fine the selection using the arrow keys to start it in the middle of the face: usually the middle of the mouth and the middle of the tip of the nose ...
Operate then Edit> Copy (Ctrl + C) and then do twice Edit> Paste (Ctrl + V).
With the mouse, move left one of the two pasted parts ...
Then click on the second part to select it and run: Edit> Transform> Flip Horizontal.This will result in returning this part ...
Move it Closer the first part to complete the RIGHT face.
Same job on the left side of the face ...
Add margins to separate your images ... It's over ! You have now to analyze the character of Britney ... And that is not a piece of cake