Starbucks Rewards allows you to earn stars on every purchase you can redeem for free drinks or food. You'll need a physical Starbucks gift card or an e-gift card to sign up. Then, download the Starbucks app or visit the Starbucks website to create an account. Once you have an account, you'll earn stars every time you make a purchase through the app or with a registered Starbucks card. You get 2 stars for every $1 spent on most purchases. (Some purchases, such as wine, taxes, and tips, don't earn stars.)