Darling Nathan has asked his readers for the worst writing advice they've gotten. My favorite: "Remove all your commas. Editors don't like commas and they pull the reader out of the story."
Haha! Um, also the letter "b". Editors hate the shape of the letter b, and it distracts readers from any word it appears in.
Oh, this is so true, though. It seems like every writer's conference I attend I get asked to confirm or deny at least one piece of ridiculous advice.
Here are your antidotes:
For every piece of advice regarding punctuation, substitute: Read a good book about punctuation. Know what it is for. Know what the rules are. Then ignore them if you like.
For every piece of advice regarding how to write, substitute: Read a lot. Write a lot. Read a lot. Write a lot.
For every piece of advice regarding what to write about, substitute: Write about something you would want to read about.
For every piece of advice regarding who to submit to and how, substitute: There are no one-size-fits-alls. Do your own research. You'll learn a hell of a lot along the way.
For every piece of advice regarding ignoring all the rules, substitute: The rules are there for a reason. Understand the reason before you decide to ignore them. Then feel free.