We had fun trying out FaceTime for Mac, but we noticed something interesting: Even if you quit the app, you'll still receive incoming calls. How can you make this stop? Simple:
Head up to the FaceTime menu and open up the Preferences. There you'll find a magical toggle which will prevent random FaceTime calls from disrupting your day.
If you think that you'll forget to hit that toggle each time you want some peace and quiet, you can sign out of FaceTime each time you're done with chats and sign back in when ready for more. (You do this by tapping on the FaceTime icon on your dock and hitting "Sign Out".)