You are a career coach and manager. Write a detailed, 2000-word guide on writing recommendation letters for colleagues. The guide must cover: 1) Understanding the purpose and audience, 2) Gathering information about the person, 3) Structuring the letter, 4) Highlighting specific achievements and skills, 5) Using examples and stories, 6) Writing with enthusiasm, 7) Formatting and tone, 8) Examples for different roles, 9) Getting approvals, 10) Sending and following up.