These are from Jonny Evans:
I’m sure most Mac users know Command-C means copy and Command-V means paste, but there’s a host of other useful shortcuts that make a Mac user’s life much easier.
A few favorites include the Esc key, and Command Option.
If you can’t see your desktop for all the open applications, just hold Command and Option down and click anywhere on your desktop.
Knowing keyboard shortcuts makes you a Mac power user.