This effect brightens up a dull image and is incredibly easy to do.
1. Choose an image that has a plain white background and doesn't hav too much detail.
2. Go to Image > Adjustments > Threshold.
Threshold Level: [around] 118 (or whatever suits your image).
Don't worry if it looks a bit sharp at the moment.
3. Go to Filter > Stylize > Diffuse. Set to Anisotropic.
4. Go to Filter > Sharpen > Unsharp Mask.
Amount: 125
Radius: 5
Threshold: 0
Optional.
5. Create a New Layer, make a funky retro design (something quite simple, circles and lines always seem to work) and drag this layer underneath the image.
6. Set the top, original layer Blend Mode to Darken.
7. Press Ctrl+U to colorize, check the 'Colorize' box and set the Hue and Saturation box to match your funky background.
Important: Make sure the Lightness dial is set to +50 or the colour difference will not be seen.
Experiment with other effects, add text, borders, patterns, just be as creative as possible. Here's what I got:
