OS X has a large and impressive list of "hidden" shortcuts meant to make your life easier. Most of us do know about some of them, but I don't think there is one person that could know all of them. Mainly because each of us use our Macs in our very own ways, and the shortcuts and features that someone swears by may not be of much interest to you.
Having said the above, I do believe that by becoming aware of (at least some of) the available shortcuts, you do increase your chances of learning about a new way of making your life easier.
Here I list some of my favorites, and with "favorites" I mean some of the ones I most often use, but when I show them to others, they had no clue they were there. Probably you already know about some of these, but I hope to at least get you one ah-ha moment.
Do you have multiple audio interfaces? Do you find yourself often making a trip to the Sound System Preferences to change the input or output? STOP! Never again!
Next time you want to change the audio input or output interface, Option-click the volume icon in the menu bar. From the pop-up menu simply change either the input or output interface right from the menu.
I think I use this shortcut multiple times a day… for sure.
You may already know that for most software on the Mac, you can drag a file, group of files, or folder from the Finder and drop it on the software. But I bet that most of you did not know that you can take a file or folder from the Title Bar.
For this to work, you first have to grab the icon from the title bar to turn it into a proxy. Simply click and hold the icon for about half a second until it appears shaded. Keep on holding the click and then drag elsewhere. But the neat thing is that this works from by dragging a proxy icon from the title bar in the Finder to another application, or from within an application to another application or the Finder!
Here's an example. Imagine you're writing… say a paper on geology, and that you want to attach the Pages file that you're working on to an email. In most cases you'd save your Pages file, go to Mail, and to attach the document you'd go to the folder where the file is saved and then attach. Well, try this out: First save your work on the Pages document you'll be attaching. Next, go to Mail and start a new message where you'll be attaching the Pages file. With the Pages file still visible behind your email composition window, click the Pages document icon from its title bar until it goes dark, and then drag it to the body of your email. Effectively you'll be attaching the Pages file without having to even go to the Finder.
Neat little known fact: You can drag and drop proxy icons to any save or open dialogue box saving you the trip to the Finder.
In the old days, the Mac keyboards used to have a power button. Now these days you'll find it on a MacBook or a MacBook Pro, but not on the desktop keyboards. Well, if your keyboard doesn't have a power button and you miss it, you'll love this one: Hold the Control key and hit the eject button on the top right side.
This will bring up the Shut Down dialogue box. From here you actually have multiple very useful buttons with bonus shortcuts:
Chances are you already know and use the Application Switcher (Command-Tab) which allows you to jump to any application that is already running.
But the Application Switcher has a bunch of shortcuts on its own:
Use your mouse.
After you summon the Application switcher, simply use your mouse to quickly click on the application you want to jump to instead of pressing the Tab key multiple times.
When you call the Application Switcher and you keep pressing the Tab key, the next running app will be selected. But did you know that once you're in the Application Switcher, you can press the ~ (tilde) key to go to the previous application running? Like this: Hold Command and tap the Tab key. While you keep on holding the Command key, now tap the ~ (tilde) key.
Command-Q or H
Yep, while you're in the Application Switcher you can quit or hide the selected application right from the Application Switcher. Hold the Command key, tap the Tab key to engage the Application Switcher, while holding the Command key use the Tab or ~ (tilde) keys to select the app you want to quit or hide, and while still holding Command tap the Q key to Quit the selected application or hitting the H key will hide it instead!
I don't use this one as much since I don't get too many notifications throughout the day. But if you do get a lot and sometimes just want to turn them off to concentrate on a task, you could go into the Notifications on the right edge of your screen, scroll to the very top and enable "Do not disturb".
Shortcut: Option-click the Notifications icon in the menu bar. When you see the icon turn grey, that means Do Not Disturb is enabled. Option-clicking on the icon again will toggle the icon to black, meaning that you've just disabled Do Not Disturb.
There are a lot of other shortcuts in OS X. These are just a few of the ones I use. Some I've learned by looking for them, others from seing someone else using them, and a few by pure mistake (like the audio interface pop-up menu).