This is some of what I do in school.

Left side is the messy version of a tree that does the exact same thing, but other people needed to be able to use it so I made it neat (right).

If you are wondering what you are looking at, the top right teal rectangle contains image input sequences for background, water, and key, fill and rimlights for the character. The layers are then individually colour corrected (sometimes with roto masks) and merged, in addition, filters are applied for things like blur, chromatic abberation, vignettes. At the bottom is the output, which renders an image sequence or a video file of the whole thing.

I finally figured a way to tint colours that I will be able to remember. It's a lot like flowchart photoshop I guess, so the benefit is I can reuse the comp on similar footage - like the other shots from this set.

I'm very slow at compositing, and, given that I want to work in vidya games maybe not too interested, but it's alright. Being able to kill highlights/specs in some section of the image, for instance, is a huge benefit and it doesn't even look fake.