use guidelines a lot and I usually invoke a guideline with a right click + Add Guideline. It gets a bit tedious after a while. Do you know a way to add a guideline with a keyboard shortcut + a click at the desired location, like, for example, Shift+Alt+Left Click. A shortcut that places a vertical Guideline in the middle at the active window would also be suitable.
I’m using guidelines as a “scaffold” to adjust glyphs, like when i need to keep strokes parallel, check if all serifs are the same dimensions, when I need to extend elements proportionally, and so on.
I’m also using them like a rotation gizmo - i draw e rectangle and rotate it to the desired degree, line a guideline to the desired angle and delete the rectangle. Like when, say, I create a bolder version of the letter K and need to keep the angles between the elements the same.
I also open corners to prolong lines.