You probably already know, in most applications you can jump from data field to data field by pressing the Tab key. Did you know by pressing Shift + Tab you can go in reverse order through these fields?

For example, if you visit a web page, you can press tab to jump to the different hyperlinks and input fields throughout the page. If you overshoot your desired target, you can simply press Shift + Tab to go backwards instead of having to go all the way through again.