Begin by finding a texture you like. I found this one that I obtained from Swim Chick. Then right click your image, and press "Paste as New Layer." Right now you should be viewing only the texture. Then locate your layer palette and setting the 'Raster 1' to screen 100& like below:
Your image should look like so: (depending what image and what texture you have chosen)
To take this tutorial a little further, let's fix their faces which are a little faded. Grab your 'rectangle' tool which looks like below:
and set it to my settings:
Then make a square only on their faces, which comes out like this:
and press Delete.
It should look like this:
Then to finish this tutorial, layers>>merge>>merge all. Then duplicate your base and set to soft light 100%, make some borders and you should end up with something around this:
and set it to my settings:
