One of the handiest tools in an artist's toolbox is the humble ruler. Whether it's a regular straight ruler, an at-square, or a set of French curves, rulers can really make a difference to your artwork, which is why the digital rulers in Clip Studio Paint are some of my favorite features. I actually first started using Clip Studio Paint (back when it was known as Manga Studio) because I saw a demonstration of the perspective ruler tool and knew that I needed to have it in my workflow.
Ruler tools in Clip Studio Paint work just like straight rulers or curved rulers in real life, except that they're digital – and they can be customized and made to produce certain special effects easily, such as all lines going to a specific focal point (or even curving to a specific focal point). If you draw or ink in the digital realm, you want to make sure...