ONE. Choose your base image/s and arrange them however you want. (If it’s just the one image, obviously you don’t have to change its position.) It’s best if you use two similar photos because the natural lighting and colouring of the photos will change the final product.
TWO. Layer>New Adjustment Layer>Levels. The aim with this step is to add contrast by making both the darker and lighter colours more bold.
Input Levels: 32, 1.18, 255
This will vary depending on your image, but play around with it until you get the desired effect.
THREE. Layer>New Adjustment Layer>Selective Color. I use selective colour on almost every graphic I make. It’s used to bring out certain colours that are already in an image. Again, this will vary depending on your image and the desired colouring you want, but this is what I used:
Yellows: 0, 0, 0, -100
Greens: +100, 0, 0, 0
Cyans: +100, 0, 0, 0
Blues: +100, 0, 0, 0
Magentas: 0, +50, 0, 0
Neutrals: 0, 0, +15, 0
Blacks: 0, 0, 0, +21
FOUR. You can choose to stop there if you want as this next step is optional. Make a new layer and fill it with #5D0505. Set it to Lighten, 100%
And voilà, you’re done.
This doesn’t work on every image, but if it has a lot of dark colours, it will usually have a pretty nice effect.