In this Photoshop tutorial I will show you how to add a bottom shadow.
Open your image in Photoshop (File >> Open).
Create new layer (Layer >> New >> Layer) and Set foreground color to black.
Now select a soft brush. And set diameter little smaller than shadow size you want to add.
Click once just below the shape to which you want to add shadow.
Go to: Filter >> Blur >> Motion Blur
And apply following motion blur settings.
Pres ctrl + F 2-3 times to re-apply blur motion effect. Bottom shadow effect is added to your image. See the image after adding bottom shadow effect using motion blur.
Download PSD file of the tutorial FREE