Pop Art - part 1

Remove the background of your portrait photo.
1-Make a rectangle:
file>new
and then type in the number of pixels or inches or cm you prefer. I used 36x47 cm.
Use the eyedropper to pick a bright color and fill the rectangle with the paint bucket.
2-Use the rectangular marquee tool to make a smaller rectangle (a few mm smaller than 1/4 of the big rectangle) inside the big one.
3-4-Make four rectangles that size and give them each a different bright color.

Copy/paste the portrait in each rectangle. Resize it so it will fit the rectangle perfectly.
edit>transform>scale (press shift while change the size to keep the proportions)

Highlight the portrait layer in the layer window.
Use the eyedropper to put black in the foreground box and white in the background box.
filter>sketch>torn edges
Change the balance, smoothness and contrast to get the perfect black and white image.

The result of the "torn edges" filter.

Use the eyedropper to pick a color (you can go with the 4 background colors or go with 4 new colors) and fill the white parts with the paint bucket tool.