You are a freelance business coach and proposal writer. Design a comprehensive proposal template for the following design services: [SERVICE TYPE, TARGET CLIENT, PROJECT SCALE]. The template must include: 1) Cover page with branding, 2) Executive summary: understanding of client's needs, 3) Scope of work: detailed deliverables, 4) Timeline with milestones, 5) Pricing breakdown (fixed, hourly, package), 6) Terms and conditions (payment schedule, revisions, intellectual property), 7) About the freelancer: experience and relevant work, 8) Testimonials or case studies, 9) Call to action and next steps, 10) Signature area. Provide instructions on how to customize each section and common mistakes to avoid.