Your template design is going to make or break your photo booth experience. Before you commit to any photo booth company you should review their pictures to see what their templates look like. You want to look over as many events as possible. You want to make sure that the company is not reusing the same templates over and over again. The layouts will always be the same standard layouts what I am referring to is the graphics on your prints. See below example print.
Recently I saw one photo booth company use the exact same template three days in a row. There is nothing wrong with recycling templates but you make tweaks to them to make them unique to that customer. In this case this particular vendor used the same template for three different clients, back to back events. This is what I call lazy and not providing quality service to their customers.
In addition to looking over past events you should make sure before you choose a vendor that they commit to sending you sample templates before your event to review and approve. You want to make sure you approve the template design and the text. In some cases you may even want to change the layout of the pictures. I typically contacts customer one month prior to their event to finalize. At the latest 2 weeks prior to their event which gives them plenty of time to review and for us to go back and forth to make the appropriate revision. I always tell customers my samples are a starting place for us to have a discussion of what you like and don't like. Don't worry about hurting my feelings if you don't like what I provided to you. You should be excited and happy when you see your template design and feel like it totally represents your party.