There is an easy way to simulate this ‘neon glow’ effect (also known as ‘painting with light’) by adjusting a photoshop brush. Learn how to make a brush taper, change colour, and fade.

Step 1
Make a new document, filling it with a dark background colour. You may also want to use a photograph.
Click on the Brush Tool. Using the default, select Brushes to enter the options menu.

Step 2
Select Shape Dynamics. Change Size Jitter to 22%, change Control to fade (at 200), change Minimum Diameter to 81%.

Step 3
Select Colour Dynamics. Change Control to fade (at 300). Change Purity to 0%.

Step 4
Select Other Dynamics. Change Control to fade (at 300).

Step 5
Check Wet Edges, Airbrush, and Smoothing.

Step 6
Select a bright neon foreground colour, and a near-white background colour. Drag your brush around your canvas, and you’re painting with light!

You can adjust your brush if you want it to fade faster, longer, etc. Adjust the numbers after ‘fade’ to experiment!