I just published my no-nonsense beginner's guide to printing maps and assets to scale using the GIMP image editor. (maps and assets also included!)
Find it on my blog: https://2minutetabletop.com/gimp-how-to-print-map-assets-to-scale/
It's particularly useful for our assets, character tokens, and customized maps, and explains how to print them with a perfect 1-inch grid scale. It's a question that comes up rather often, so I'm glad to finally share my personal method.
If there are any more guides you'd like to see, please leave a comment! I'm really happy to make guides such as these when I know that they'll be used. :)