Bringing food is always a safe bet. Flowers are a touchy subject, and no one needs another candy dish.”
I say a bottle of Moscato is a safer bet. Everyone drinks wine (this one happens to be great), or if they don’t they can re-gift it to someone when they are invited out, or put it in a shalach manos to the machetonim. Food is a tricky item, because a) the hostess already cooked and b)there might be someone allergic in the family. We can never accept homemade food unless the guest checks with us on the ingredients, because a member of my family is highly allergic to sesame and other seeds, and presumed allergic to nuts, as well. So everything has to be checked and triple checked that it has no traces of those items. This is harde than one would think, as even equipment in a facility where nuts and seeds are processed can affect an item NOT made with those items. So check with your host.
A nice thing that someone did recently was to make a frozen dessert (first asked me if it was ok) in a lovely ceramic tart pan, and the pan and the dessert were a gift. After the first time, I would not want, much less expect someone to bring me a “hostess gift,” but the first time someone eats in my home, it is a nice thing for them to do, even a small token. I was brought up to do so. I have had people who never brought anything, other than their appetites, and I still invite them. Though it should not be expected, it is proper to show hakoras hatov in the form of a gift of some type even in a small way.