Okay, so vampire spells in fantasy novels—I find they’re less about a strict recipe and more about the symbolic currency they’re built on. Most rituals need a source of power tied to the vampire mythos, which usually means blood, of course, but specifically the blood of the caster, the target, or sometimes a sacrifice. Then there's often a temporal component; midnight or the dead of winter pops up a lot, linking the act to themes of death and stillness.
Beyond that, you'll see a lot of elemental opposition. Things like ashes (fire’s end), grave soil (earth), maybe water from a specific cursed river. The incantations themselves borrow from a mix of faux-Latin and the author’s own invention, but the intent is always about transformation or binding—trading humanity for immortality or chaining a will to darkness.
I keep thinking about how in some of the darker romantasy takes, the spell ingredients become metaphors for the relationship. The 'common ingredient' isn't just a herb or a gem, it’s the willing surrender of something precious, which, frankly, gets more interesting to read about than another list of bat wings and wolfsbane.