Opinions may vary, but I believe the right way to do steampunk - aside from Steam Boy - would be that your world had modern technology of a high level AT FIRST, but then something screwed up and destroyed civilization. You start over, and there's alot of this old tech lying around that doesn't make sense because you've only figured out clockworks, pulleys, steam engines, and so on. So, you examine these things to see what they must be for. And once you realize that, the gears get turning and you say, "Well, I think I can recreate this bit of lost science myself, with the right tools. If I recreate some of the parts of this device and hook it up to my engines, I'll be able to toast my bread and keep food cold to preserve it longer!". So basically, steampunk should be about restoring technological advances using that level of development.