AFP Conference Roundup: Best Practices for Annual-Giving Campaigns

The letter's first and last paragraphs should both include your ask, and then repeat the ask throughout the letter. Use the body of the letter to create urgency around the ask; use a tone that assumes they'll give; and thank them in advance for their gift. Pranger recommended writing your acknowledgment at the same time you're writing the letter text, and having the acknowledgment letter signer be the same person that signs the appeal letter.