Here is a nice little tutorial to show you how to electrify your images with lightning in Photoshop.

On a new layer, create a black to white gradient, diagonally from the top left, to the bottom right.

Filters>Render>Differance Clouds

Now invert the image. Cmd/Ctrl+I

You can start to see the lightning

Adjust levels to bring out the lightning, Cmd/Ctrl+L.

In the levels box: slide the black arrow to the right and the middle one to the right too, until it looks nice and clean

Now to add a bit of color:

Go to Hue/Saturation Cmd/Ctrl+U Click the colorize box and slide the Hue till you like the color.

Now to add it to your image:

Just place the lightning on a layer above your image and change the layer blending mode to "screen". Here I duplicated the lightning layer 2x and rotated it a little.