How to talk to a returned missionary.

Note: this post is primarily directed to the family and friends of returned missionaries.  All RM's are invited to review it for accuracy.

You have waited for this day for a long time.  You stand in the airport, scanning the crowds.  Your loved one has been gone for so long it seems.  If you don't recognize them from before or the pictures they sent periodically, at least you should be able to spot them from the name tag.
There they are!  The two of you run, meeting each other half-way in an embrace.  The next few moments are a blur of happiness, with the crowds seeming to disappear.
So, now that they are home, how do you talk to them?  You love them, miss hearing their voice, and want to be able to relate to their experiences and become reacquainted with them, but are unsure of what to say.  They aren't much help at times, seemingly lost in a faraway land and unknown (to you) times and faces.  To help you in this endeavor, I will my personal, insider's opinion.
First of all, talk about their mission; they want to talk to you, but are as lost as you are.  All they know for now is the mission field, and they often miss it very much.  Talking about it reawakens the joyful experiences they had, and rekindles the joy they felt before.  It also makes the transition back to everyday life less drastic.
So, how do you talk to them about it?  Ask specific questions.  They have 11,680 hours (or 8,640 hours for Sisters) of waking experiences as a missionary from which to draw upon.  It will be very hard for them to just relay stories without some kind of prompt.  Saying, "tell me about your mission" is an invitation, but not a prompt.  So below I will include a few possible questions you may consider:

Ask about their ties (for Elders).  Elders often collect ties (as it is one of the few variables to their daily attire), and almost every one has a story of how he got it.  This can also open up avenues to hear more about their companions.

Watch a movie with them that is centered on a mission or missionary work (The Best Two Years, Errand of Angels, etc.).  This will provide lots of opportunities to ask something like, "did that ever happen to you?"

Ask them what area they grew the most in, who was their favorite companion, who was one of the families they grew close to, and why on all of these.

Don't use yes or no questions.  Asking open-ended questions will allow them draw on their memories and share them.

Ask to see some of their pictures from the mission.  Warning Note: only do this if you have a lot of time on your hands.  Many missionaries will have accumulated thousands of photos, and it will take some time for them to even show the highlights.  If you choose this route, feel free to stop them and ask questions about the pictures that seem to have a background story.

In all things, just show interest.  These returned missionaries have loved their chance to serve their Savior full-time, and doing so has brought many joys.  Sharing those memories with you will make them happy, as well as deepen your relationship.