How do you use a Starbucks card?

Simply present the card to the barista when making your payment. If there's enough money on the card for the purchase, you're good to go. If there's not enough money on the card, you can ask the barista to reload the card with money by paying in any of the usual methods. You can also use a Starbucks card to accrue points toward free drinks and special offers with the company's rewards program.