OK... Mrs. Irish and I were just discussing this over coffee, and we took a look at our phones and here's what we came up with:

1. Put your phone on "Do Not Disturb" mode.
2. Go to set-up in "Do Not Disturb" mode and make these settings...
3. Set it so only your "Favorites" can call and text. You should be able to edit who your favorites are.
4. Alternately you can set it so only someone in your "Contacts" list can call or text.
5. Set it so any other calls will have to call back within 15 minutes in order to get your phone to ring. If you even want to do this.
6. Set it so that you will get alerts from your calendar and alarms also if you wish.

I just set my phone up this way today and we'll see how it goes. I'm going to leave it like that all the time now.