[header] How to buy a promise ring [title] Decide what finger the ring is for. [step] Promise rings traditionally go on the ring finger of the left hand, and are replaced by the engagement ring if you and your partner get engaged. However, there is a much looser code when it comes to promise rings than there is with engagement or wedding rings. 
Pick what finger seems right for you and your partner. [substeps] If you don't want the promise ring to eventually be replaced by the engagement ring, consider buying the promise ring for a finger other than the ring finger.