A standard popular drink from the 1920s that I enjoy today is a Gimlet. 4 parts gin, 1 part Roses sweetened lime juice, 1 part ordinary lime juice (fresh or bottled). So 2/3rds booze, 1/3rd non-booze. It’s a rather stiff drink.
Cutting that about 50/50 with club soda in a tall glass makes a much more relaxing afternoon cocktail rather than a post-dinner stupor-inducer.
If you’re not a gin fan, the flavor profile w vodka is similar. Tart, but not too tart, and not sickly sweet like so many afternoon cocktails.