I’m a browser hopper.
I use a browser for too many hours a day and sometimes I just have to change browser, just to try something new.
Today it was the turn of Safari.
I like Safari, a lot. It’s light, no-frills, and very fast.
However, while opening a new tab with cmd-W I accidentally pressed cmd-Q, quitting the browser.
Chrome and Firefox provide a nice, optional confirmation dialog when trying to close them:

Safari does not have it.
So I re-mapped the cmd-Q to cmd-option-Q.
Here’s how I did it: open System Preferences, and click Keyboard:

Click Shortcuts, then App Shortcuts:

Add a new shortcut, choose Safari and call the Menu Title “Quit Safari”, and add the new shortcut:

There it is:

Since this has the same title of the existing Quit Safari menu, the shortcut will now change:

No more accidental quitting.