Praying for guidance is typically the first step to choosing a patron saint for a Catholic confirmation. In addition, you can research various saints and consider the ones you share an affinity with.
People are drawn to various saints for a variety of reasons, including that they wish to emulate them or because they share their station in life or vocation. Catholics view an individual's vocation as her unique way of serving and glorifying God. For example, a woman who feels it is her vocation to serve as a maternal figure not only to her own children but to those of her neighborhood or community may choose St. Anne, the patron saint of homemakers and mothers. Someone who enjoys traveling and spends a great deal of time away from home is a good candidate for St. Christopher, the patron saint of travel.
Others choose patron saints based on their professions. For instance, someone who composes or performs music for a living is apt to choose St. Cecelia, the patron saint of music.
When all else fails, some people choose a saint based on a life experience dominating their consciousness at the time of confirmation. St. Joseph of Cupertino, the patron saint of school and studies, is a popular choice among those putting tremendous effort into obtaining a degree, for example.