The reason this sprang to mind is because the bus I took home also carried a loud-voiced guy whose most-used filler word was "fucking". As in "Yeah, and nearly the first fucking day the fucking place was open? Some fucking guy loses his whole fucking finger."
I work with eighteen-year-olds. The f-word does not bother me. It really has become just an innocuous (to the person using it) filler word. The only reason this guy's use bothered me was because (1) he was loud enough I couldn't ignore him, (2) I was hungry/tired/too hot/cranky, and (3) bloody hell, buddy, you say it every fifth word. Learn to say "um", would you?
Broadcasters train themselves not to use filler words.
Writers likewise train themselves to prune their prose. To quote the perfect advice of William Strunk Jr. in The Elements of Style, "Omit needless words."
I've gotten decent at not using "that" when it isn't necessary, and I omit things that are implied - "Annoyed, she got off the first bus and caught the next
Like all the "rules" of writing, omitting needless words isn't a rule at all - it's a form of training that breaks you of bad habits. You're better off aware; the rules teach you to see your writing, and to thus see its weaknesses. Once aware, you can fix the problems.
What "rule" of writing has helped you most in becoming a better writer? Why did it help so much in your particular case and what were you doing before?