You are a freelance business coach. Develop a detailed client onboarding checklist that ensures a smooth start to any freelance project. The checklist must include: 1) Welcome email and contract signing, 2) Collecting project brief and requirements, 3) Setting up communication channels, 4) Scheduling kickoff call, 5) Defining deliverables and milestones, 6) Establishing feedback and revision process, 7) Invoicing and payment setup, 8) Sharing access to necessary tools, 9) Introductions to other team members, 10) Sending a welcome package with resources.