Being a fan of alcohol generally I thought I had the perfect G&T figured out, until I substituted Meyer lemon for the key limes I normally use. Wow! I would also highly suggest it in your vesper as well.
Perfect G&T for me: tall glass, Rim slice of lemon or lime around glass, muddle lightly. 2 oz. Tanqueray 10 or Hendricks gin, top with ice, swirl. Add tonic water. I haven’t found anything better than Canada Dry but I am in the boonies.
Perfect Martini: 2 parts above gin, 1 part Polar Ice vodka, from freezer. add to shaker with a light splash of Noilly-Pratt or Martini dry white vermouth. Add generous amount of ice to shaker, and swirl, not shake, 50 times (because). Add 3 jalapeno stuffed, or feta stuffed olives. Make sure the glass is really nice looking because that matters. I like mine in a Mikasa martini glass.