I think my first experiment with this would have been aided by having better cheese. My bleu was nothing special and while the dressing was better-than-commercial, it wasn't especially memorable or exciting. The base amount of buttermilk ended up being pretty pulpy and I ended going nearly double with the buttermilk.
lemon juice or white wine vinegar
a few drops
red wine vinegar
Combine blue cheese, salt and pepper, breaking up the cheese crumbles. Mix in sour cream, buttermilk, lemon juice, chives and red wine vinegar. Adjust seasonings and buttermilk as necessary.