@Pete Perez: Yea, I haven't been able to find much either. That's why I tried to give it a shot and ask.
You're probably way ahead of me, but for those who'll read this thread one day and don't have a clue about what to write here's what I've learned about marketing.
1. Get to the point: On social media you have 3 sec to get someone's attention. The same with letters. Before anything else let reader know why they received your letter, which is the purpose of the letter.
2. It's about them not you. Whenever possible replace 'you' with 'I' or 'we'. We only care about ourselves. We don't care about you. A rule of thumb: ask yourself after each sentence "what's in it for me?" That's what your reader thinks while reading through your letter.
3. Speak on their level. While 'property' may not seem like a word most people don't understand, using the word 'home' or 'house' depending on the situation to makes it easier to digest and is more familiar. Write in plain English.
4. Less is more. Once you're done writing, read through the letter and ask yourself what you can leave out without losing the point and still make sense.
5. Give them as multiple ways to contact you. If you just leave a number and they prefer email, you lost them, and if you only leave website, but your website is down, they spelled it wrong (especially if it's a long domain name) or they just prefer to call, then you lost them. Give them options. 3 is the magic number when it comes to choice.
5. EXTRA: No more than 3 lines per paragraph. A long paragraph can be demotivating to read, since it requires a lot of their time and effort to get to the point/essens.