I kept losing my cursor on a big monitor. PowerToys Mouse Utilities fixes that with Find my mouse, Mouse Jump, and Crosshairs ...
For years, one of my favorite Gems has been MondoMouse, a utility that lets you move, resize, or identify windows without having to first switch to them, and without having to position your cursor ...
On Gnome (a linux desktop environment) I can move/resize a window (even if it's not active) by holding the meta/command key and using the left mouse button to move, or the middle mouse button to ...