I draw inspiration from the Vampire the Bloodlines: Masquerade series a lot - so I like the idea of various clans with their own traits and rivalries. Some adhere very strongly to the masquerade and blend in with the normal crowd.
I like the idea that Lilith and Caleb are Toreador-esque, and I always recruit Marcus Flex into their fold as the first one. I don't know why :P I just see Marcus as a vampire ever since it first happened.
I also like the idea that powerful sims may be powerful vampires (such as the Feng family), who's got their own supply of ghouls and a vampire restaurant, which was once a lounge, for Vampire shennanigans to ensue out in the open. (You really shouldn't visit if you're a walking bloodbag, haha).
I give Vlad one teenage son, who's drunk on power and cannot control his cravings - nothing like his stoic, misanthropic old man. This until Vlad reprimands the young man for bringing shame to the Straud family name.
Vlad seeks a family he feeds of from every few nights (it's usually the Pancakes every save haha), or the one that has the Divine Flavour - they get commanded around to ensure he has his opportunity to strike without too much hassle (no witnesses alright!). He then hibernates during the day, and composes his intricate music during the night, while his son continues to misbehave (no feeding of off the butler though! That's prohibited).
Due to starting over a lot in the past, my saves haven't gotten the chance to fully flesh themselves out - as it's a continuous work in progress to establish connections, clubs and experience emergent gameplay. But I'm committed to one save now, so it's starting to come together.