Whether you’re coming across from a Windows machine originally, or you're a Mac veteran, Mac OSX offers many keyboard shortcuts that you may not be aware of. Mastering these shortcuts can dramatically increase your efficiency:
Command + Tab – Cycles through apps, similar to Alt+Tab in Windows.
Command + ` – Switches between windows of the current application. (` is the key in the top left of the keyboard, not to be confused with ')
Command + Option + W - Closes all open windows of the current app.
Command + , – Opens up the preferences menu for most apps
Command + H – Hides current window
Option + Shift + Command + V – Pastes text with no formatting, to strip different fonts and colors away
Command + Space - Launches a Spotlight search, letting you quickly launch apps and open documents
Option + Shift + Command + Space - Opens a windows with spotlight so you can search for files on the Mac.