To master any application, your fingers must memorize its hot keys—the keystroke combinations to navigate without the mouse. You probably know most of the basic ones, such as Ctrl-C for copy, but there are tons more in Windows as well as in every desktop app.
Don't sit down and study a hot-key cheat sheet. Instead, try KeyRocket. It runs in the background while you use Word, PowerPoint, or Excel, suggesting shortcuts as you need them. Simple analytics also show how much time you’re saving. The full version costs $30.