Easier Said Than Done: 25 Tips for Better Fundraising Copy
14. Use wrong grammar. I'm not suggesting you be churlish and deliberately make stupid mistakes. But sometimes getting it right makes you come across as a schoolmarm, which, unless you're an actual schoolmarm, is pretty unsympathetic. For instance, correct use of "whom" doesn't sound natural to most people (and it's probably dropping out of English). Any correct grammar that people don't commonly use in speech is a candidate for flouting. And if that's too painful, just revise so you avoid the issue.
15. Replace at least one paragraph that's about you. Instead, make it one that is about your reader.
16. Limit paragraphs to seven lines. Long paragraphs are forbidden territory. Anything more than seven lines is long. Most paragraphs should be one to four lines.
17. Break up long sentences. Long sentences are the main cause of thick, unreadable prose. Any sentence more than 20 words is probably too long. Keep ?sentences closer to 10 words. Or less. Really.
18. Read your copy out loud. This is one of the best ways to make sure your copy is clear, colloquial and easy to read. If you stumble while reading, sound pompous or arrogant, or just come across as an idiot, your copy needs more work.
19. Cut your first paragraph. I'm not kidding. It's like magic. Most likely, your first paragraph is a warm-up — and your real lead is your second or even third paragraph. Give it a try. It's one of the quickest and most surefire copy revisions I know.
20. Make the letter longer. I know you wouldn't read a long letter. Neither would I. For all we know, nobody reads long letters anymore. But we do know long letters work. Every time I've tested this (except once a few years ago), longer letters worked better than shorter ones. Add another page, and you'll almost surely get more response.