Research vampires. To write great vampires requires knowing all about vampires. You need to dig through the historical myths, legends and lore. From this, you need to gleam those key elements required to make a vampire a vampire, those things that readers will expect, those things that will make your vampires seem real and give your writing authority.
Read what's already been published. If you are to write something great, it can't be a rehashing of what's already been done. Therefore, you need to know what has been done and overdone. Find out what directions other authors have taken the vampire.
Make your vampire unique. While all vampires are based in legend, every literary vampire has differences, at least the good ones do. Find some new twist you can give the age-old bloodsucker. Great vampires make readers think, Why hasn't anyone ever thought of that before? It doesn't have to be the vampire himself that's different. It can be the rules of vampirism that change.
Have a compelling story to tell. Having a cool vampire isn't enough to make the novel great. You must have something (some message) you wish to impart in your story. Any great novel must have a strong plot and believable characters we care about. Give your vampire a motive and goal that readers will root for. Or if your vampire is the villain, make him one the readers will love to hate.
Find your author voice and write in a clear style using proper language. Clean writing that is unambiguous and easy to follow never goes out of style. If your writing is hard to follow, readers won't bother trying to decipher it, and editors will reject it. Make sure you have a good command of the language and its rules of grammar.