I missed the Mac function of being able to color files and folders. Then I figured out how to make custom icons for Windows. I do it all the time, usually because I don't like the design of the standard icons or it is too small. Also for important folders that I want to POP. As a Designer I enjoy the challenge of creating a logo that reads as well at 16x16 pixels as it does at 256x256.
It is quite fun to.do this kind of thing. I had to for a while as I was making and still occasionally do make Rainmetrr skins with a dock or quick launch skin for my most used applications.
Usually I do very flat things though, something undistracting, just to blend in with the background as these just sit on top of the wall paper.
My icons are all over the place style wise. My style is no-style. depends on what it's for.
BTW: I use Pshop at 512x512 pixels and save as a 256x256 .png, usually with transparent areas. Then I convert to .ico with free Junior Icon Editor. It's important in Pshop to view the potential icon at various sizes. From tiny 16% zoom up to 200% when I'm working on it.
I am all AMD and poor people as Barnaclues would say so I use Paint.net. I do send out as PNG because I don't need to use ICO for thenreainmeter skins. It treats fully transparent as non clickable so I usually have a full square background of practically invisible 001 transparency layer to make the entire icon area clickable. But my uses are different a little from yours.