Mavericks added a useful organizational tool to OS X that you’ve probably overlooked. Finder tags let you assign keywords and labels to files and folders on your Mac, in iCloud Drive, and even in some third-party file sharing services, like Dropbox. That means even if you prefer to litter your Desktop with files, a simple search can easily gather everything you need for a project ①. Finder tags aren’t much help with the files you already have unless you’re ready to put in some work, but they’re easy to add as you create new files.
① Tags let you find files easily on your drive, iCloud, or even in your Dropbox folder. If you designate colors for tags, a tagged file appears with a colored dot (or dots) by its name in the Finder.
When Tags Make Sense
What would you use Finder tags for, anyway? You could, for instance make a Taxes tag and apply it whenever you create a file that you’ll need when tax time comes. As your deadline approaches, click the Taxes tag in the Finder sidebar, or do a search for the tag, and all files with this label appear.
You’re not limited to using one tag. A file might include several—for instance, Urgent, Take Control, El Capitan Book. Use tags to identify projects, indicate time pressures (Urgent, Waiting, Finished), label Home versus Work items, and more. Tags are a flexible system that you can tailor to the way your brain works.
Set Up Your Tags
To set up your basic tag system before you start tagging, go to Finder > Preferences and click Tags ②. Rename a tag by clicking its name, pausing, and then clicking again. It becomes editable and you can type in your replacement. Click the plus button to add a new tag or the minus button to delete one. Drag the tags in the list to reorder them.
② Go to Finder > Preferences > Tags to set up your tags or change them later.
Click the dot next to a tag’s name to change its color. You’re limited to the eight basic hues (including the “No Color” color), but more than one tag can share a color. If you choose a color, the tagged file will appear with a colored dot by its name in the Finder.
For easy access, drag your favorite tags to the box at the bottom of the Finder Preferences window. These tags will be included in the contextual menus. Or, add or remove tags from the Finder window sidebar using the checkboxes at the right.
You can also create new tags on the fly whenever you tag a file using any of the methods I explain next.
Tag Your Files
When saving: The easiest way to tag a file is when you save it. Below the filename field, click in the Tags field to choose from a drop-down menu of all your tags, or type in a new tag (or existing tag) and press Return to apply it.
When the file is open: In many apps, you can click the file’s name in the title bar to see a Tags field ③ that works just like the one described in the previous bullet item.
③ When you’re working on a file, click its name in the title bar to see an option to add tags.
In the Finder by dragging: Drag a file in the Finder and drop it on top of the appropriate tag in the Finder sidebar.
In the Finder with a click: Another way to drag an item in the Finder is to Control-click it to open its contextual menu and then select a tag from the list you see there ④.
④ Control-click a file in the Finder to see your tags (circled) in the contextual menu.
Or, if you don’t see your tag, or you want to create a new one, choose Tags. A field appears with a list of all your current tags below. Here you can choose a tag or type the name of a new one (or an existing one). Press Return to apply it.
Tag from the Keyboard
If you prefer to keep your hands on the keyboard, set up a keyboard shortcut for tags. Go to System Preferences > Keyboard > Shortcuts and then click App Shortcuts.
Click the plus button and choose Finder from the Application pop-up menu. In the Menu Title field type Tags… using either three periods or the ellipsis (Option-;). (In the past you had to use a proper ellipsis or this wouldn’t work, but Apple has removed that obstacle.)
Next, click in the Shortcuts field and enter a shortcut, for example Command-Shift-T. Now when you select a file in the Finder, use this shortcut to jump straight to the tagging window ⑤.
⑤ Select a file in the Finder and press your custom keyboard shortcut to apply tags easily.
Remove a Tag
To remove a tag, Control-click a file in the Finder. In the contextual menu that appears, select the one you want to remove in the list of tags.
If you don’t see the tag you want in the list, choose the Tags item instead. A list of all your tags appears. (If you have a lot, choose the last entry, “Show All.”) Tags that are applied to the file will appear in the field under “Assign tags to ‘ItemName.’“ Select the one you want to remove and then press Delete.
Find Tagged Files
To find all files labeled with a tag, click the tag in a Finder window sidebar. Alternatively, search for the tags by pressing Command-F to start a Finder search. In the search field, start typing the name of your tag. A drop-down menu appears with matches ⑥. Choose your tag to gather up all its files.
⑥ Type the name of a tag into the search field to see a drop-down menu appear with tags that match.
If you need to search for more than one tag, it might be easier to type their names into the search field. For instance, type tag:TagName and press Return. (Replace the word TagName with the actual name of your tag.) Then, for your next tag, type tag:TagName and press Return ⑦. This creates an AND search. In other words, your search will only find files tagged with both tags.
⑦ If you’re searching for items tagged with multiple tags, enter each one in the search field by typing tag:TagName and pressing Return.
Create a Smart Folder
If you want to be able to use your search again, turn it into a smart folder. For instance, I might create a smart folder that finds all files with my Urgent and Take Control tags.
In the Finder, open a New Smart Folder window by choosing File > New Smart Folder. Near the upper right, press the plus button to create your first criterion. Choose Other in the first pop-up menu, select Tags, and then type your tag name into the field. Add and subtract criteria as you please and then click Save when you’re done. Name the smart folder and save it somewhere convenient.
Smart folders look like regular folders, except their icons contain small gear images. Smart folder contents update dynamically according to the criteria you’ve set, which means they’ll always include your newest files that match.
button to add a new tag or the minus 
button to delete one. Drag the tags in the list to reorder them.
