Freeze the coupe 5 minutes ahead. Nothing in this drink holds temperature once it leaves the tin -- no ice in the glass, no carbonation. The glass is the only thermal mass it gets.
This is the craft-bar Gimlet, not the naval one. The original Royal Navy version was gin and Rose's lime cordial, unshaken. This fresh-juice-plus-syrup build is the modern standard and tastes brighter and less syrupy.
Fine strain, not just the Hawthorne. A hard shake with fresh lime pulls in small ice shards and pulp. The mesh catches what the shaker's built-in strainer misses.
Adjust syrup, not gin. If your limes run acidic, nudge the syrup up toward 5/8 oz rather than adding gin -- the gin-to-citrus ratio is what makes it a Gimlet.
Juice extra limes while you are at it. Fresh juice keeps 2-3 days refrigerated, and fresh versus bottled is the difference you can taste blind in this drink.