Mojito's aren't bad cocktail wise - rum(2.5) / lime juice(0) /mint(0) /soda (0) / sugar (at home I replace for sweetner, free)
G&T is my main tipple, but rum n diet coke is OK if they run out of slimline tonic ...
My old C introduced me to syn free (non-alc) pimms - (you might have to take my word for this, but it is surprisingly good) In a large jug put loads of orange slices / cucumber / strawberries etc .. add 1 litre of sugar free lemonade then add 2 tablespoons of balsamic vinegar.