User Stories are a great way to express and document items in a Backlog, and foster a conversation within the team on what needs to be done. This is a useful template for User Stories, and can be used for Features as well. There is also a template for Epics in another page.
You can print this template on two sides, then cut the User Story cards. One side is for the User Story description (“As a … I want to …. so that…”). The back side is for the Acceptance Criteria.
The card also has space for priority information, including the values needed for WSJF (or other prioritization method you may prefer).