Creating a valley of snakes illusion

1. DOING THE GROUNDWORK
Start by applying a red to green gradient in radial mode.

Change the gradient mode to difference in options bar at top. Apply gradient several times.

Duplicate the layer. Scale down vertically and place as shown.

2. OVERLAYING SNAKE SKIN ON BACKGROUND
Select main gradient layer. Duplicate the layer, From filter mane select "distort>>stained glass". Apply settings as shown.
Change the layer mode to "Pin Light".

Repeat the same technique for the ground layer too.
3. HISS.. SNAKES ARE CREEPING IN
Insert a cutout of a snake. Play around with the layer mode and opacity.
Insert more snake cutouts and change their layer modes and opacity.
Insert a big cutout of a snake. Reduce opacity to very low value and change the layer mode to "linear dodge".

Insert cutout of a lady and place as shown.
Press Ctrl+L to open level settings. Apply settings as shown.
4. CREATING ILLUSION GLOW
Select and merge all the layers. Duplicate the layer. From "Filter" menu select "Blur>>Gaussian Blur ". Apply settings as shown.

Change the layer mode to "Linear Dodge".