Even though pixel art isn’t used much in the world of branding, I still find it to be an interesting artstyle. For those looking at getting into video game development, this is also a handy tutorial.
The author, Derek Yu, presents a few things that will help polish up your pixel art skills. This includes dithering, aliasing, and light sources for outlines. There are programs created specifically for pixel art, but this tutorial is mainly for users of photoshop.
Below is a time-elapse of the image used in the tutorial. It gives you a good idea in the process involved in this.