1. Open the picture you want to work with. If you want it icon sized, it should be 100 by 100 pixels.

I'm using a photo of a toy sundae.

2. Go to Image- Adjust- Levels. Type a 2 in the second box and press ok.

3. Duplicate the layer, and change the second layer's blending style to Overlay.

Make a new layer and fill it with #FF00FF. Change the blending mode to Color Dodge and lower the opacity to 30%.

5. Make another new layer, change your color to white, and draw a single white spot in the upper left corner using a soft brush size 200 (or around there). Change the blending mode to Overlay. Save your icon and you're done!