Mine is using the arrow keys to navigate typed text while writing and editing. It helps speed things up, versus having to move your hand to the mouse to navigate.
Use the Up and Down Arrows to move/jump vertically.
Left and Right Arrows to move/jump horizontally.
Combine Left or Right Arrow with Shift to be able to select text. Use Up or Down Arrow with Shift to quickly select whole/nearly whole sections of text.
Combine Control with Left/Right Arrow to jump whole words to more quickly move to where you want to type.
Custom autocompletes/corrects. Just figure out a non-word (i.e. something that you wouldn't want to use without autocorrecting) that's easy to remember and set it up frequently used snippets of text. Some examples:
meetnow - my zoom meeting link
booktime - a link to my calendly
frequent sentences or blurbs I use in emails (e.g. thanks so much, let me know if i can help with anything else sorta stuff)
nicknames for different frequently used hex codes
galert/yalert/redalert populate a styled HTML snippet to make a green, yellow, or red div that I can then just pop my content into
lots of other little HTML snippets like that
group nicknames to populate a list of email addresses (like an Outlook contacts group but you can use it outside of Outlook)
Anyway there are a ton of things I use it for, those are just a few examples. Saves me a lot of time.
You can do this on Macs at a system level, on Windows you can do it on some programs but it seems to have to be set up on each one which is worthless.