Let me put this simply, most favors don't make it home with your guests. As lovely as you think something is, not everyone will be as excited to bring it back home. Here are some tips to ensure your favors get taken home and waste is avoided.
DO make it something that represents you as a couple. For instance, if you got engaged in Italy, consider something like Olive Oil.
DON'T put your names or date on it. If it's a removable sticker or it's something they can use despite like honey or another food item, leave it off. It's unlikely they will often find a use for a cup with your name and wedding date on it.
DO make it edible! People love food so anything like chocolates or honey are far more likely to get taken home.
DON'T put it at place settings. Make it an optional item to take as they leave to avoid extra clean up if they get left behind on the tables. This is especially important if your dinner and dance are happening in separate areas as they may not return to their table.
DO make sure it fits in your budget and vision. Favors are not required.
DON'T order too many, typically about 60%-70% of your guests on average will take the favor. This is especially true if it is not at the place setting. If it is a place setting item you will of course need one for every seat.
DO consider having your favors pull double duty like acting as the late night snack or their table assignment.
Here are some wedding favors we love.