(CNN) -- For the better part of a decade, superheroes on the big screen have been big business ("Iron Man 2" the most recent example). On TV, however, keeping audiences coming back each week for the exploits of those with superpowers has been a far trickier task. It's been a long time since "Batman," "Wonder Woman," "The Incredible Hulk" and "The Greatest American Hero" hit prime time. One show that has been able to get it right is "Smallville," which begins its record-breaking tenth season Friday night on the CW (that would be the longest consecutively running sci-fi show). What began as a revised history of Superman's teen years in Smallville has come a long way over the years, with Clark Kent fighting crime in Metropolis as a rarely-seen hero called "The Blur," the introduction of Lois Lane, and other superheroes occasionally joining the fray.
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Producers, writers say make the heroes believable
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Give the characters a good backstory
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Give the time travel gimmick a rest, says Kring
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