- Never shut off your Mac by pulling the plug. Always use the Shut Down command from the Apple menu in High Sierra (or press the power button and then click the Shut Down button). If you're using a laptop, you can usually get away with pulling the plug while it's running because the battery automatically kicks in. The only caveat is that if your battery is totally depleted, damaged, or missing entirely, you could suffer directory damage or data loss by pulling the plug. Just use the Shut Down command, and you'll sleep well.
- Never bump, drop, shake, wobble, dribble, drop-kick, or play catch with a hard drive while it's running High Sierra. Don't forget: Your desktop Mac has a hard or solid-state drive inside it, too.
- Never get up from your Mac without saving your work. Just before your butt leaves the chair, your fingers should press Command+S (the keyboard shortcut in macOS that saves your work). Make it a habit.
- Never keep only one copy of your important documents. Make at least two backup copies and keep one of them in another physical location. Period.
- Never clean your monitor with a glass cleaner, such as Windex (or another product not designed to be used on a video display). And nix the paper towels or tissues, too. Use a soft cloth (microfiber is best) to avoid scratching the display.
- Never pay attention to anyone who says that Windows 10 is just like the Mac. Yeah, right. And a Kia is just like a BMW.