I have an idea:
Stay away from the Twilight design. Twilight has seriously damaged the image of vampires and werewolves both. If you want reall vampires and werewolves you watch Underworld.
Anyway, plot idea:
-Give it a twist. Instead of a guy vampire, why not have the girl be the vampire? Yes, and she really likes some guy and at first he really hesitates and doesn't like her because she's a vampire, so it takes time and trust for him to accept her. Of course when he does, you just know that some other guy, maybe a vampire, likes the chick as well, so now he is in a big mess and has to fight, not just for the girl, but to for his own freakin' life! But don't make the chick save his life... that is simply far too corny, even for a romance tale.
Anyway I'm sure since it's a romance that involves vampires, instead of a vampire story that involves romance, it will probably be Twilight-ish, but that's your choice and it's your story so it's cool
my brain... not on drugs