1. Grab your picture, here I'm using the lovely (almost 18) Olsen Twins..
2. Go to Image > Adjustments > Threshold and move the slider untill you have something that looks like mine. You'll get the hang off it after a few tries.. it's not that hard
3. Create a new layer (Shift + Ctrl + N) underneath your picture and apply a Lineair Gradient from top to bottom to it with these colors (or the ones you like)
Foreground: #FFAA05
Background: #FF6600
Now change your picture's layer blending mode from Normal< to Soft Light (in my case: the Olsen Twins picture)
4. Now it may look a little bit jagged because of the Threshold filter you apllied on your picture, so go to BLUR > GAUSSIAN BLUR and chose a small radius to get rid of it
There you go Your back in the 70s
Here's Anna K. again for all the fans out there..
More Tutorials: 
