- Ctrl + Cmd + Shift + 4 will let you take a screenshot of a region of your screen and copy it to the clipboard. It can then be pasted directly into most applications, from email clients to chat clients. No random screenshots sitting around. If you want to capture a whole window, press Space after the initial shortcut, then click the window.
- While a menu is open, hold Option; if you're lucky, you'll get some additional options. This works after right-clicking an item in Finder, for example, or after right-clicking an icon in the Dock.
- Magnet for window management. This is a third-party application, but you'll wonder how you lived without it. If you've used Spectacle, Magnet is similar, but I find Magnet to be a bit more graceful.
- Sidecar and AirPlay. Want a second screen? Got an iPad or Apple TV? You can effortless treat it as a second screen with very low latency. It "just works."
- Cmd + Space to open Spotlight. Most power users are already familiar with this; if you're not, try it.
- Cmd + Shift + G in Finder to go to a folder by path. You can also use it to copy the path to the current folder.
- Return/Enter to rename the currently-selected file in Finder. If you're coming from Windows/Linux and are accustomed to pressing F2, you might not know about this one.
- Similarly, to open the currently selected item in Finder, press Cmd + O. To navigate up a directory, press Cmd + Up.
- Ever installed a new drive in your Mac? You don't need to manually download macOS installation media beforehand; with the right key combination at boot, you can install it via the internet. There are a few different related combinations with differing functionality; it's worth looking them up and choosing the right one for your situation: https://support.apple.com/en-us/HT201255
After you press Ctrl + Cmd + Shift + 4 and start dragging a region, if you hold the space bar, you can move this region around the screen so you're not trapped with where you originally started dragging.
Cmd-Shift-5 for some more nice screenshot options, including disabling that floating window that appears before your screenshot gets saved to the Desktop
⌘-Shift-5 to disable that floating screen shot thing... I love you. That thing is _so slow_ and distracting I always worry my screen shot didn't actually save until that slow window popped up on some random screen.
You can even have it automatically open on an iPad to annotate on– I cannot overstate how useful this is when you're trying to write instructions for something.
If you're using a Macbook with a Touch bar, you can press Cmd + Shift + 4 to enter a screenshot selection mode, and then use Touch bar to adjust screenshot mode (full screen, window or selection) and destination (Desktop, Clipboard, Preview, Documents etc) on the fly.
After pressing Cmd + Shift + 4, press Space and then click on a window or alert to screenshot it entirely, instead of having to drag out a rectangular region. It works at the level of the compositor so the screenshot includes its chrome and translucent drop shadow, and nothing behind or overlapping the window,
ctrl + cmd + shift + 4 was what first came to mind. For the longest time I did cmd + shift + 3 and did the rest manually.
cmd + ctrl + o to open another tab in Finder in the same folder that's current open. In my opinion this should be the default for cmd + t, which opens a new tab but in your home folder.
For the app icons in the top right, clicking while Option is pressed also shows different menus. For example, the wifi icon now has options for diagnostics or the battery icon has a battery quality indicator.
- While a menu is open, hold Option; if you're lucky, you'll get some additional options. This works after right-clicking an item in Finder, for example, or after right-clicking an icon in the Dock.
- Magnet for window management. This is a third-party application, but you'll wonder how you lived without it. If you've used Spectacle, Magnet is similar, but I find Magnet to be a bit more graceful.
- Sidecar and AirPlay. Want a second screen? Got an iPad or Apple TV? You can effortless treat it as a second screen with very low latency. It "just works."
- Cmd + Space to open Spotlight. Most power users are already familiar with this; if you're not, try it.
- Cmd + Shift + G in Finder to go to a folder by path. You can also use it to copy the path to the current folder.
- Return/Enter to rename the currently-selected file in Finder. If you're coming from Windows/Linux and are accustomed to pressing F2, you might not know about this one.
- Similarly, to open the currently selected item in Finder, press Cmd + O. To navigate up a directory, press Cmd + Up.
- Ever installed a new drive in your Mac? You don't need to manually download macOS installation media beforehand; with the right key combination at boot, you can install it via the internet. There are a few different related combinations with differing functionality; it's worth looking them up and choosing the right one for your situation: https://support.apple.com/en-us/HT201255