The glass is part of the instrument.

Glassware sits between the drink and the person. The opening, the weight, and the point where the hand meets the glass change the experience of serving.

Start with the practical requirement. A measured pour needs a vessel that sits securely. A drink served over ice needs enough space for the ice and the liquid. A long drink needs room for its mixer.

A collection does not have to be extensive. A stable rocks glass and a tall glass cover many familiar recipes. Choose pieces you enjoy using, and let technique do the rest.