Dinner with the phones in another room
One shared meal with the phones elsewhere, practical exceptions agreed and no obligation to turn it into a lifestyle.

Put them somewhere you can't see them
For one dinner, agree to leave your phones in another room. Not face down between the glasses. Not balanced on a knee. Somewhere you would have to get up and go to.
That's the whole proposal. You don't need to announce a digital detox or establish a new household philosophy. Make dinner, sit down and see what the meal is like without a screen within easy reach.
If that sounds too simple to deserve an article, good. It should be easy to try.
Ask before the food arrives
“Shall we put the phones away while we eat?” is enough. Make it a shared choice, and put yours away too.
Don't spring a confiscation bowl on guests, appoint yourself the table's inspector or turn another person's reluctance into a verdict on the relationship. The point is to give each other some attention, which becomes rather harder if the evening begins with an argument about obedience.
There can be sensible exceptions. Someone may be on call, waiting for news, caring for a relative or using a phone for a medical or accessibility need. Agree what works around that. A phone kept available for an important call is doing a different job from one being checked between every mouthful.
You can also start smaller. Just the main course, perhaps. Choose a period everyone is willing to try rather than treating endurance as the achievement.
Make the practical bits easy
Finish anything necessary before sitting down: checking a delivery, finding the recipe's last step or letting someone know you'll reply later. Then leave the devices in the agreed place.
If someone needs urgent calls to get through, they can choose a suitable setting and check that it works. There is no prize for accidentally becoming unreachable when somebody depends on you.
You don't need to make the room theatrically silent. Music is fine if you like it. So is an ordinary meal, with ordinary plates, on a night when nobody has produced a particularly impressive dinner.
Don't replace the phones with a programme
You are allowed to talk about the day. You are also allowed to talk about a film, something ridiculous at work or the neighbour's ambitious fence.
Avoid arriving with an agenda for a “meaningful conversation” unless everyone wants one. Putting the phones away doesn't create an obligation to disclose something important. Sometimes an enjoyable meal consists mainly of passing food and laughing at a story somebody has told before.
If a question comes up which you would usually settle by searching, let it sit for a while. You can find out later which actor was in the film. Not knowing for twenty minutes is survivable.
Equally, if there's a good reason to get a phone, get it. One interruption doesn't invalidate the evening. This is a meal, not a purity test.
Finish when you've finished
Afterwards, pick the phones up if you want to. There is no need to rate the experience, record a streak or extract a promise about every dinner from now on.
You may have enjoyed the extra room in the conversation. You may scarcely have noticed. If it suited you both, suggest doing it again another night.
For now, someone is still at the table and there may be a little food left. Ask if they'd like some.