Trying to remember how I used to do mine...it's been awhile...people said they liked them. I probably went with a basic recipe (using either mayo or Miracle Whip) and I liked to add zing, like a wee bit of finely chopped sweet pickle and/or some (mild) mustard and/or a bit of hot (tabasco-style) sauce. Maybe a wee bit of English mustard would kill the latter two bits with one stone? (I've known of people including vinegar, olives, different herbs & spices, and the paprika thing definitely! Also have seen a recipe that mixed tinned tuna with the yolks for the stuffing. Guess it all depends on the taste you're going for -- but it's definitely a creative thing to experiment with!)
I haven't made them over here yet -- DH doesn't like eggs, neither does his mum, and so we don't tend to have eggs for family get-togethers, etc.