When we were in Miami this winter, we went to this restaurant Barceloneta, which has a large gin and tonic menu. They serve them in big goblets, with lots of tonic (Fevertree is their favorite), so they aren’t as strong as usual. One of the tricks we learned from them is that they like to grate the lime zest into the drink to finish it off. It’s become the way we make our g+t now (although we still keep them short and packed with a big punch). One thing to note: don’t do the zesting if you don’t have really fresh limes, because the zest then is dry, and ends up just being annoying.