Modify a photo via blend modes

Step 1 - Open the photo
If it isn't already open, open the photo you wish to modify. Also, make sure the Layers palette is displayed.
Step 2 - Duplicate the Background layer
Choose Layers > Duplicate. This creates a layer named Copy of Background. You'll be modifying this layer.
Perform this step for me.
Step 3 - Set Blend Mode to Overlay
On the duplicated layer, click the Blend Mode drop-list (the current blend mode should be Normal), and choose Overlay. Expand the Layers palette horizontally if you cannot see this option.
Perform this step for me.
Step 4 - Adjust layer transparency
Adjust the duplicated layer's transparency setting from 100 to a value below 50 percent. For most photos, you'll get the best results between 20 and 40 percent. Select this step's script to set this value to 30 percent.
Perform this step for me.
*Optional* Step 5 - Toggle visibility on and off
*Optional: To see the effect on the photo, click the duplicated layer's Toggle Visibility icon on and off.
Notes and Tips:
The Overlay blend mode tends to help produce more vivid colors. Experiment with other blend modes (as well as Adjustment Layers) to create interesting effects.

Learn More:
One Step Photo Fix
Create soft focus - Manual
Create soft focus - Automatic