Surrounding a cobra on a girl's body

Start by opening an image of a lady.

Insert a cutout of a snake.

Click add layer mask button from the bottom of the layer palette. Select black as foreground color and mask the unwanted overlapping areas.

Double click the layer to open layer style window. Apply settings as shown.

Similarly create snake around the girl's head. Use snake's upper body and mask out rest of the area.
Create selection of the area as shown using polygon lasso tool. Press Ctrl+J to copy paste the selection in a new layer.

Move this layer above all the layers in layer order in layer palette.
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 "Overlay" and opacity to 50%.