One page per member instead of a folder behind the desk: phone, address, date of birth, emergency contact, the health questionnaire, the agreement they signed on screen, their documents, and notes only staff can see.
Every member gets an ID the moment their account is made — GP-0001, GP-0002 and on — so the desk finds anyone by name, phone number or member ID, and a member whose phone is flat can still be checked in by number.
The members list says where everyone stands without opening anything: their package, next expiry, what they paid, their discount and any balance due — and filters to the members who owe.