When you’re filling out a form online, to move forwards or backwards in text fields press Tab or Shift-Tab. For drop-down menus, Tab to select it then press Spacebar to expand it. Use the up and down arrow keys or…
In Safari, Chrome, or Firefox, to open a new Tab press command-T. To open a link in a new Tab and keep the current page at the forefront, hold command when you click the link.
To quickly select an icon in a Finder window, just start typing the first few letters of its name. Make sure you type quickly if you want to be specific.
To move pages from one PDF to another, open both PDFs in Preview, go to the View menu and enable "Thumbnails", then drag the page thumbnails from the Sidebar of one PDF to the Sidebar of the other.
In any dialog box or error message, pressing Return will select the blue (default) button. Pressing Escape is the same as pressing the Cancel button. In many applications pressing the command key and the corresponding key for the first letter of…
To hide the front-most application, press command-H. To show all the hidden applications again, go to the Application menu (just right of the Apple menu) and select Show All.
To switch between all your open applications, hold command then press Tab repeatedly without letting go of command. To quit one of those open applications, press Q when that icon is selected (without letting go of command).
To activate Quicklook in the Finder, highlight a picture, document, or video and press Spacebar. To get out of Quicklook press Spacebar again or click the little grey X in the top left corner of the Quicklook window.