There was a time when one of the most thrilling things to do was to refresh your Mac with a set of brand new icons. Moving from 32-by-32-b&w-pixels up to 1024px with millions of colours apparently crippled the availability of good looking, professionally done icons (the only sets that are both high-quality and decently up-to-date are made by David Lanham and I don't even know if he has any plans about them for the future).
Since I'm a customization junkie, I had to create some myself. Despite my previous work with BehindTheRabbit I'm not a professional designer, so I have to use some dirty tricks and stick to the basics.
Since I'm really bad at drawing, for my personal icons I often use free/open source/GPL webfonts like FontAwesome, IcoMoon, Typicons or Ionicons: they all have a SVG version which makes them perfect for a vector app like Sketch.
Most of the times I just combine some basic shapes (square for drives and volumes, round for folders, diamond or cog for scripts...) with colours, borders and icons in order to create something neat and easily identifiable.
I'm sharing some of them (along with - in some cases - their source files).
You can find here some scripts too.
[Note: This page really is a work in progress... ]