Part of our trip planning for France 2016 focused on staying connected with family and friends, not to mention the internet. The internet part pretty much took care of itself since WiFi is widely available in France.
It was the phone side of the communication equation that presented the real challenge.
A large part of that challenge was met head on two years ago when we bought an unlocked phone with a Vodaphone SIM card in Great Britain, a phone we still have and which I will use during the trip. (It turns out that I had to buy a new SIM card, though. The process, which we did at the SFR store, was straightforward enough and went smoothly.)
For my wife, though ,we were faced with either buying another "burner" phone or using her Verizon iPhone. To use Verizon we simply added the least expensive international plan ($40/month), which gives her enough minutes and texts for the time we will be in France.
The other Verizon option, as I understand it now, is to unlock the phone's SIM card slot and then use a SIM card, preferably one purchased in France with a French phone number. I have labored under the belief, not well-founded apparently, that the phone was locked forever. That's not true.
You can indeed unlock the phone's SIM card slot and use a separate card as needed. (If you have the iPhone 5 or 6 you can see the SIM card slot on the side below the on/off button.)
Of course, this does not apply to ALL phones or all devices for that matter. And you have to request permission to unlock the slot. Also actually changing the SIM card for anyone not used to doing such a thing can be a bit complicated. The first thing to do would be start with the nearest Verizon store to get the latest update about how to actually go about using a different SIM card overseas and how can install it properly.
That said, we will definitely explore using a local SIM card next time.
You can find helpful information on using a SIM card with your iPhone in Verizon right here.