You are a proposal content strategist. Create a detailed guide on developing content for business proposals. The guide must cover: 1) Understanding client needs and proposal requirements, 2) Proposal structure: executive summary, approach, deliverables, pricing, 3) Template development for reuse, 4) Case studies and credentials, 5) Visual design for proposals, 6) Personalization strategies, 7) Proposal management tools, 8) Measuring proposal win rates, 9) Examples of successful proposals, 10) Iterating based on feedback. Provide templates and examples.