Here's another way the word it cues weakness in a sentence. You know how writers are sometimes advised to eliminate the word as? Usually, we're talking about problems of simultaneity, but not always. Sometimes, it's just plain old wordiness.
Watch for the word combo, as it.
She listened to the roar of the crowd as it erupted from the sports stadium.
You can kill as it and get a stronger sentence.
She listened to the roar of the crowd erupt from the sports stadium.
It's still wordy, but it's better, and this is a very easy fix to spot and to make.