rajanrayhan, thank you for your kind words. I'm probably not the best person to answer this question, because I treat every Hub differently, depending on the Hub. That's not the best approach because some that might otherwise get better traffic don't do as well as they could/should. One thing I never do is social bookmarking (but again, I'm not recommending that approach, or "non-approach", to anyone).
Chances are, someone else who has more of a "formula" for promoting Hubs will be better able to offer helpful information here than I can. The eclectic mix of Hubs I have just makes it impossible to really give one, clear-cut, answer.