You are a business consultant and copywriter. Write a detailed, 2000-word guide on executive summaries. The guide must cover: 1) Purpose of the executive summary, 2) Structuring (hook, problem, solution, market, team, ask), 3) Writing concisely and persuasively, 4) Highlighting key metrics, 5) Tailoring to the audience (investors, lenders), 6) Editing for impact, 7) Examples of great summaries, 8) Common mistakes, 9) Getting feedback, 10) Using it in pitch decks.