The general approach to writing a proposal is to create an argument for some sort of policy change by way of specific formatting and structure. Proposals are divided by headings for easy navigation and reading.  Proposals might argue for funding, approval for some type of activity, ideas for a future project, and so on. Some basic components to the proposal are:

• Background (situation, issue at hand, reason for writing the proposal, problem in need of addressing)
• Executive Summary (not always required: a summary that synthesizes the proposal’s main points for easy reading)
• Body (space where argument takes place; may include methods, budgets, timelines but overall supports the proposal’s main points; the body can be broken down into many subcategories)
• Conclusion (may include a call for action or recommendations for further work)

See also Tips on Writing a Grant Proposal and Grant Proposal Writing Tips.