The short answer
Start with the food, not the drink: is it fresh, creamy, roasted, or spicy? Alcohol-free isn't a flavor profile. It leaves all the possibilities open to you.
Three alcohol-free companions to try
Unsweetened tea, well chilled, pairs nicely with mild vegetables. With a hearty barbecue platter, a bitter alcohol-free beer can work well. With roasted dishes in sauce, an alcohol-free red wine with a bit of tannin is worth trying.
These are suggestions to experiment with. What matters most is the individual bottle and how the dish is prepared. There's no drink that pairs with everything — not even among alcohol-free options.
Pay attention to the sweetness
A very sweet drink quickly overwhelms the whole meal. So taste it with a full bite in your mouth, and check the sugar content on packaged products. When alcohol is removed, a wine's style changes. That's why the same grape variety name won't taste the same as in the alcoholic bottle.
Sweetness is the most common pitfall here, and it adds up. A sweetish drink alongside a dish with honey, balsamic, or roasted root vegetables quickly turns cloying. Something bitter pushes back and can be enjoyed throughout an entire meal.
Guests shouldn't get a fallback option
Offer the alcohol-free drink just like any other: properly tempered, in the right glass, with a sentence to introduce it. Water is perfectly fine here too. No one has to drink sweet soda just because they don't want alcohol.
In practice, this means: the same glass, the same care with temperature. A good alcohol-free companion served in a water glass looks like a second-best choice. Served in a wine glass, chilled and briefly introduced, it holds its own on the table. That costs nothing and changes the whole evening.