The size decides what you use it for
The size decides what you use it for. A coupe of 16 to 22 cl is the cocktail size: a shaken or stirred drink of around twelve centilitres sits nicely full in it and does not slosh over when you pick it up. A coupe of 26 to 33 cl is the champagne size, and you fill that no more than halfway so there is room left for the aroma. If you want to build a champagne tower, choose a model with a wide, flat foot and a sturdy stem, because only then do the glasses stand stably on one another.
Then look at the rim. A rim that turns slightly inwards keeps the liquid in better and carries a garnish, while a fully open coupe looks more elegant but spills sooner. Pay attention to stem thickness as well. Lehmann makes thin, refined stems in series such as Paris, London and Roma that impress on the table, while Onis and Arcoroc are sturdier and last longer behind a busy bar.