For me - since I try to plot out the villain's actions in my head before writing them down, I tend to reveal the villain to the reader and let the villain's actions speak for him.
Unless the villain is like Tempus (knowingly embracing evil for the sake of excitement and chaos - and even in his head he's doing good - the safe, boring world of the future cannot be good for the long-term survival of humanity - most villains will see themselves as having good (possibly noble) reasons for doing what they're doing. They're just misunderstood. (Villains love Nietzche.) And since the good guy doesn't explain himself...
