Organize the outcome, not just the files.
A folder full of final assets is a beginning. Add a clear index, explain which version belongs where, and separate everyday files from working documents. Name things for the person using them next.
Carry the decisions forward.
Capture the choices that shaped the work: the approved direction, the important constraints, and the usage notes. Those details help a client make good decisions after the project team has stepped away.
Make next steps specific.
Say what is complete, what the client needs to do, and who to contact with questions. If a follow-up is part of the scope, give it a date. Clear endings make future conversations easier.
Close with a conversation.
Leave room for questions before calling the project finished. Walk through the handoff together, then send a short recap. The work is more likely to live well when the people receiving it feel confident.