Feras Alhlou on closing projects right: don't hand off work and vanish. Document everything, train your client to use what you built, get their feedback, and make sure they can actually run it without you.
Most consultants rush or overlook closure. There should be a closure on 2 fronts, between you and the client and internally, especially if you're working with a team. For closure with the client, don't just send over the final deliverables and move on. Document the handoff properly, provide training and enablement, even if you did not explicitly include it in the proposal. Make sure the client can actually use what you've built and ask the client for feedback. Which you can use in your internal closure processes.
