I'll try to get back to the forum a couple times a day to add new tips to this thread.
And, of course, I'm hoping you'll add tips of your own so we can discuss them.
Tip: In your query letter (and anywhere else) don't say "My novel entitle XXX." The very you're looking for is "titled." This one error can brand you as an amateur and that may be enough for an agent or publisher to deep six your query--and never ask for follow up chapters. Not sure it will feel as dreadful to feature editors and radio hosts, but it's still good to avoid, right? (-:
I'll be back later with another tip.