Ring boxes are most commonly used for storing and presenting engagement rings, but they can also be used for other types of rings, such as wedding bands, promise rings, for heirloom ring.
Consider the occasion: Is this for a proposal, a wedding or just for storage? Classic velvet or leather boxes work well for proposals or weddings, while travel-sized boxes are good for storage on the go.
Think about personalization: If you're buying the ring box for a special occasion, you could consider getting it engraved with initials or a special message. While online stores might offer engraving options, some physical stores might as well.