1/ Launch apps in OS X using Spotlight — Using Spotlight to search for files etc is handy, and can also search for apps. Not only that, but as with search on iDevices, you can also use it to launch apps.
First, launch Spotlight. For most people this is Command-Spacebar (that’s the default).
When you get to Spotlight, start typing the name of the app you want to launch. If it appears at the top, just hit the Return key on your keyboard and it opens.
2/ Launch apps using a single letter — Once you have your list, you can also type the app’s first letter (like you can in Finder windows). Except in Spotlight, once you’ve typed the letter and your app’s selected, press Return and it launches.
3/ View all messages in a Messages conversation — Apple’s Messages app in OS X Yosemite borrowed from its iPhone and iPad cousins, so now you can do more in your conversations, like view all of the images and attachments you sent and received in a chat.
To see all of the photos and attachments in a Messages conversation, just click Details in the upper right corner in every conversation. You can click and drag anything from the Details view to your Desktop or folder; double-clicking an image opens it in Preview.
4/ More from Details — The Details view also lets you mute notifications for specific chats, start phone calls and FaceTime calls, and screen share. This is a handy way to see images that otherwise would take a ridiculous amount of back scrolling in long conversations. Grouping in calling features, too, as a bonus.
5/ Make sense of Safari’s new Favorites bookmarks — The new Safari look can throw you almost as much as the new iTunes. But don’t panic: choose View>Show Favorites Bar. When you drag an icon to a new location in this view, its location in the Favorites Bar change too.
If you don’t like this view, you can eliminate it. Open Safari’s Preferences, click General, and configure the New Windows Open With and New Tabs Opens With options.
To organise and edit bookmarks the old fashioned way, the shortest way to do it is to choose Bookmarks>Edit Bookmarks (Command-Option-B). This fills Safari’s window with all the bookmarks it has. Alternatively you could click the Show Sidebar button in the menubar, select the Bookmarks tab, and then click the Edit button at the bottom of the pane.
Now you can rearrange their order, rename them, edit their URL, create folders, and drag collections of bookmarks into those newly created folders. [There’s more on this from Macworld.]