Go from this:
In 5 easy steps!
Program: Photoshop CS
Difficulty Level: So easy, there is none.
Pick a base. (This technique seems to work especially well on close-up shots.)
Step 1: Duplicate your base.
Step 2: Set the top layer to "Overlay". ("Soft Light" is also optional, if you don't want your end result to be as bright.)
Step 3: From the top menu, select Filter --> Blur --> Gaussian Blur. Make sure the radius is set to 2.5.
Step 4: Duplicate the top layer. Adjust the opacity of the new layer as you see fit (I used 50% for my icon here).
Step 5: Apply this mask by ianthinae and set it to "Screen".
...And you're all finished! Feel free to experiment, too. After all, that's how we discover even more lovely techniques~