If you're not familiar with the Quick Look feature on macOS, try selecting a picture, folder, or text document on your computer and pressing the space bar. The rich preview that pops up is Quick Look working its magic. Apple introduced Quick Look in Mac OS X 10.5 Leopard and it has since gained support for many more file types natively, such as Microsoft Office and Adobe Suite documents.
I use it daily and it has become an automatic part of my workflow, a natural response to wanting to inspect a file without waiting for a program to launch and without leaving off what I'm doing.
However, the problem that Quick Look faces is support. It requires a plugin for each file type it can preview, and out-of-the-box only a handful are supplied. More obscure file types are neglected, and display only a blank pane with the file icon, name, size, and date modified. In this guide, I will detail how to add plugins to Quick Look for a richer and more useful preview experience.