TURN THE LIGHTS ON

5 EASY STEPS:

01 | Add Highlights.

Choose any color you want to use, select the smooth brush tool and add highlights to all surfaces hit by the light.

02 | Opacity.

Adjust the opacity depending on how much you want to highlight the background surface.

03 | Draw outline.

Use the selection tool to create the desired shape for the lights. For the shape, be aware of the shape of the object holding the light source and how it affects the light.

04 | Lights on!.

With the shape still selected, use the smooth brush tool to add brightness to the lights. The light source should be the brightest spot and the light should fade the further it gets from the light source.

05 | Ctrl C + Ctrl V

Copy the light layer to the other locations.

and done!