Bar tools are essential instruments used in the preparation and serving of drinks at a bar. Common tools include a shaker for mixing cocktails, a jigger for measuring spirits, and a strainer to separate liquid from ice or solid ingredients. Other important tools are a muddler for crushing herbs or fruits, and a bar spoon for stirring drinks. In addition to these, a bottle opener and a corkscrew are necessary for opening beer bottles and wine bottles, respectively. A zester can be used to add citrus peels for garnish, while a cocktail glass or mug serves as the vessel for serving the finished drink.