The Finder's Go > "Go to Folder..." (Shift-Command-G) menu item is a nifty way to access your file system.
First of all, you can use it to see hidden folders, so if you need to view /private/var, you don't have to open a Terminal window to do so.
Secondly, the "Go to Folder" window is an excellent place to paste a path rather than clicking around to get to a deeply nested folder. I use this pretty often when I'm troubleshooting. After all, if Apple's support documentation tells you to open ~/Library/Mail/V2/MailData to access a file within it, it's very quick to just copy that path and paste it into the window.
To make typing stuff in even faster, the "Go to Folder" window allows tab completion (just as Terminal does), and it tries to autofill as you type, as well. So if you type in ~/Doc and then wait for a moment, your Mac will attempt to figure out the destination and fill it in for you.
Important to note is that you aren't just limited to using "Go to Folder" within the Finder itself. The same keyboard shortcut can be used to invoke it within Open/Save dialogs, too.
You can use these keyboard shortcuts to shut down or restart Macs that have a keyboard with an Eject key. If you have a computer without an Eject key, simply replace the Eject key with the Power Button in the tips below.
Please note that key names are separated by a hyphen (-), such as "Control-Eject". You do not type the hyphen as part of the key combination.
The dialog box "Are you sure you want to shut down your computer now?" appears with options to Restart, Sleep, Cancel or Shut Down. After the dialog appears, press the R key to Restart, press the S key to Sleep, press the Esc key to Cancel, or press the Return key to Shut Down.
Quits all applications (after giving you a chance to save changes to open documents) and restarts the computer.
Quits all applications (after giving you a chance to save changes to open documents) and shuts the computer down.
Puts the computer to sleep.
Puts all displays to sleep.
Power Button (if the computer is not responding)
Press and hold the power button on the computer for six seconds to shut down the computer.
A large collection of high resolution Apple hardware icons is bundled right in macOS, including great icons for nearly all vaguely recent Mac models, iPad, iPhone, iPod, Apple TV, iMac, Mac Mini, Mac Pro, and much more, going all the way back to the G4 series.
To access the hidden hardware icon pack:
• From the Finder's Go menu choose "Go to Folder" and enter the following path:
• Scroll down until you start finding .icns files named “com.apple” followed by the hardware name
Many of these icons are what you find when using network sharing with a computer they match, but they also make for an excellent way to dress up your matching Mac, for example by replacing the generic Macintosh HD icon or anything else.
Hide inactive apps. Use Command+Option+H to hide all applications and windows except for the active app, also you can Option+Click out of a specific app to hide it as you begin working elsewhere. Hidden apps are easy to identify if you use Cocktail to enable transparent icons for hidden applications in the Dock (Interface > Dock).
Auto-hide the Dock. Hit Command+Option+D to enable auto-hiding of the Dock, summon it when needed by swiping to the bottom of the screen with the cursor. Dock is a great app launcher but keep it hidden when not in use.
Use full screen apps. Full screen apps help you stay focused and make the most of small screens. This feature was designed with Mac laptops in mind, so don’t forget to use it.
Use virtual desktops. Create new desktops through Mission Control by hovering over the right corner and clicking the + button. Use this with full screen apps to create a great desktop workflow that can be quickly swiped between.
To reset a login password in OS X Mountain Lion or later, restart the Mac and hold down Command-R to boot into the Recovery HD partition. From the Utilities menu, choose Terminal to open it. In Terminal type:
and press Return.
In macOS Sierra and macOS High Sierra, an Reset Password assistant will launch. Choose the user account or admin account you want to reset the password for. Enter a new password, confirm the new password, set (if you like) a password hint and then click on "Next" to set the new password for the account in question. Choose to "Restart" the Mac and when the Mac boots up, use the newly reset password to login to the computer.
In OS X Mountain Lion, OS X Mavericks, OS X Yosemite and OS X El Capitan, a Reset Password window will appear that will list all the bootable volumes attached to your Mac. Select the volume that contains the account you want to reset and choose the user name that needs its password reset. Enter and verify a new passwords in the appropriate fields and, if you like, enter a password hint. Click Save and the new password is applied to the account.