Advanced Green Screen Techniques for After Effects

I've always enjoyed using Keylight, the built-in After Effects chroma key tool. It offers so many more refinement options than the standard chroma key effect. If you are an After Effects user, I'm sure you have developed your own methods and best practices for using Keylight. However, editors will inevitably run across footage that's very difficult to key cleanly, whether it's stray hair, translucent fabric, or talent who decided to wear green on the day of the shoot.

To date, my go-to method for these difficult situations has been to duplicate my footage onto separate layers in After Effects and use a combination of masks and various Keylight settings to control the key. Recently, however, I came across this video from 8-Bit Digital TV that provides even more useful Keylight techniques that I've already started to adopt. 

Watch the video and then leave your tips in the Comments section below.