Set the following layer effects for these shapes:
blend mode = screen, bladk drop shadow with blend mode = overlay and size = 2-3px.

In new layer, select Pen tool and create a shape with silhouette of a frog. When ready, duplicate the layer (you will need 2 copies of silhouette). Hide one of duplicates.

Create layer mask (Layer menu - Layer mask - Hide all). Then, with large soft white brush, draw inside the mask to only reveal parts of frog silhouette touching the leaf.

Then, hide this layer, select duplicated silhouette, rasterize it...

Apply Gaussian Blur (with large radius, 10-30 px), and set layer opacity to 80%.

Voila! Here is how all our layers look together.

 

The last touch is: create new layer between frog silhouettes and leaf background, set layer blend mode to overlay, select very large white brush (300px or more) and put very big dot - it will be our light source. That's all!

Frog wallpaper (see wallpaper).

Author: Vlad Gerasimov
URL:    http://www.vladstudio.com