Give people the right copy and access.

An offline marker, a synchronized folder and an exported file have different dependencies; verify the one you actually need.

Share a deliberate selection of copies, not the master root, and inspect what the recipient can actually access.

Give people the least access needed for the task; helping identify a photo does not automatically require deletion or resharing rights.

Collect contributions separately from accepted masters, then review ownership, duplicates and context before merging.

An expiring or revoked link can restrict future access through that route; it cannot reliably retrieve copies already downloaded.

A collaborator’s account region can matter even when both people live nearby; check the sharing method before reorganizing accounts.

Inspect the exported sharing copy and its context; a safe-looking thumbnail may still carry information you did not intend to disclose.

Test the recipient task—viewing, downloading or contributing—not merely whether the owner can open the link.

Hand over a documented task and appropriately permitted copies—not an account password or an assumed right to transfer ownership.