1/ Fast sound changes from the Menu Bar — The Sierra Sound menu bar makes switching audio input and output sources even simpler.
If you don’t see the Sound menu bar item – it looks like a little speaker and sits at top right of your monitor – go to Apple menu>System Preferences>Sound and check ‘Show volume on menu bar’. Now you can click the speaker icon in the menu bar to adjust your Mac’s volume.
2/ More sound control — Clicking the Sound item in macOS Sierra’s menu bar lets you set the volume and output. Prior to macOS Sierra, you had to hold down the Option key and then click the Sound menu bar item to show output options, to change between your internal speakers and headphones, for example. But in Sierra, your output options are always visible, while Option-clicking adds input options to the bottom so you can quickly switch between your internal microphone and your fancy podcasting mic.
Switching speakers without needing to Option-click may not seem like a big deal, but it’s one of many little improvements that all add up to a more efficient interface.
3/ Rearrange your Menu Bar — Before Sierra, you could move some of the system icons, but not the third-party ones. Now, nothing’s off limits except Notification Center (the three-lined icon), which stays pinned to the right. Just hold down the Command key on your keyboard, then click and drag any icon to rearrange things at top right.
4/ Export multiple albums in macOS Sierra — Click the grey Albums header in the left sidebar. It looks more like a label than a button, since it’s just the word ‘Albums’, but click it. On the Albums view this takes you to, you may see individual photos from the last album you were in. If so, click the left-facing arrow at top left to get back to the root Albums view. Here you should see all of your albums as thumbnails. From here, you can choose to export entire albums just by clicking on them. But if you shift-click for a continuous between-click selection, or Command-click for several individual albums, you can select multiple albums together and export them all at once. Now choose Export from the File menu …
5/ One for the aficionados: detailed CPU info via the Command Line — It’s easy to get general hardware information about your Mac from ‘About This Mac in the Apple menu, but the command line data, thanks to UNIX being pre-loaded on every Mac, can provide extra tidbits that the GUI leaves out. Here’s how to reveal additional detail of your CPU from the Terminal app.
Open Terminal (it’s an app on every Mac, and it’s in your Utilities folder in the Applications folder) and either type in carefully, or (much easier) paste:
sysctl -n machdep.cpu.brand_string
Then press the Return key. Here’s mine: