A couple of people have e-mailed to ask how to crank up the power in a proposal. I always try to hit a couple of things in mine (spoilers for If Angels Burn follow):
1. Offer a strong premise, one that can be easily described in ten words or less.
Plastic surgeon abducted by disfigured vampire.
2. Present a big idea.
The vampires aren't the monsters, the humans hunting them are.
3. Use conflict that is strong, has staying power, and isn't simple to resolve.
The compassionate surgeon despises the vampire for infecting and nearly killing her, and destroying her medical career. The billionaire immortal vampire who needs no one now needs the surgeon to treat other, tortured vampires. P.S., they're also falling in love with each other.
4. Throw secondary character gasoline into the story fire.
The surgeon's brother is recruited by the guys hunting the vampires. The vampire's king wants to use the surgeon's blood to create an army of new vampires.
5. Twist it, twist it, twist it. I usually have two minor and one major big twist in a novel. Too many will make it cluttered. Too few or too simple a twist leaves the story feeling flat.
The surgeon's brother thinks an ordeal he goes through is part of an initiation into the order of the humans hunting the vampires. In reality, they're torturing him to make him into their puppet to get at his sister and her vampire lover. The vampire lover is the one who tells the brother the truth.
Things that slog a proposal:
1. Too much backstory. We don't need that much life history, and we don't want to relive it through a thousand flash backs when you've run out of things for the character to do.
2. Too many pointless characters. This is a book, not a mall food court. If a character doesn't serve the story, kill them.
3. Romance-specific: heroes who are brainless beefcakes and heroines who couldn't think their way out of a paper bag. Stop living in the eighties, ladies. They're over.
4. Conflict that a five-year-old could resolve while watching cartoons and playing GameBoy.
5. Not enough passion for the story. Don't write anything just to write it. Write it because you love it. Because you can't stop thinking about it. Because you get a thrill every single time you open the .doc file. Because if you talk about it at the dinner table one more time, your family is going to stab you in the heart with their forks. That kind of passion.