[ OT ] How to go about writing a good vampire character ?

Just a few points to consider, to maybe help you expand your variety of characters a little: 
 
 * If the character is older than a normal human lifespan, then have them act that way. It's a cliche of too many vampire stories that they all act like hormone-addled teenagers, when they're actually centuries old. Make them emotionally mature; capable of understanding complicated motivations or conveying complex feelings. 
 
 * How does the character feel about the various aspects of their condition? It's common to portray a vampire as being a blood-fiend or, alternatively, a blood connoisseur. To go in a different direction, maybe have them just view blood as a food that they have no particular interest in ( like a TV dinner ). Instead, focus on the _other_ aspects of the Curse. Were they religious, and are now unable to enter holy ground? Were they a shut-in who thought they'd never miss the Sun, but now craves it? 
 
 * How does the character view humans? The common trope is that vampires view humans as cattle, or pets. To tie into the maturity granted by inhuman lifespan, maybe have them view humans as being exceptionally immature children. Instead of viewing human lives as expendable, or human problems as insignificant, maybe they view human life as something to be preserved at all costs. After all, humans are fragile creatures with short lives; it would be a horrible waste to have them cut even shorter.
