This is also a rebloggable Tumblr Post!
A lot of people were asking me how I did the glowing/neon light effects on my last drawing. It's actually extremely easy, and it looks great with shapes or text.
The key to this effect is contrast. Your background and overall image must be pretty dark for it to be effective. You know how you can't see a flashlight in broad daylight? The same applies here.
Step one, make a new document, and invert the default black background (command + i) or manually fill it with black. Then make A NEW LAYER. This is the layer containing the colors you want to glow.
Now duplicate the layer you just made