Don't Use Adverbs
Pfft. I'm immediately skeptical of any claim that advises you to eliminate an entire part of speech. Adverbs exist for a reason.
Some writers do have a problem with sloppy or redundant use of adverbs. What I mean is, a phrase like "she whispered quietly" is a well, duh moment for a reader. And some words like very, pretty, really, etc. can have their meaning diluted when used excessively.
But adverbs that actually do their job--that is, modify the verb--I propose should be used as often as necessary. I once saw someone on a writing forum say that instead of saying "she said quietly" one should just say "she whispered," but another user rightly pointed out that whispering and speaking quietly are not the same thing. Using a mix of adverbs along with a variety of strong verbs adds nuance to your writing.
I believe you should turn a critical eye on all your words when you're evaluating your work. What good is it to cut out innocent adverbs while you let your nouns, verbs, adjectives, and prepositions run wild?
English has a vocabulary of around half a million words. USE THEM!
Don't Use Names in Dialogue
I've seen a number of articles saying you should never have your characters address each other by name, because people in real life don't talk that way. This one makes me scratch my head because... um... actually, people in real life do talk that way. Names show up in IRL dialogue for a variety of reasons:
Greetings! "How's it going, Jess?"
Emphasis! "Stop it, Stephanie. I mean it."
Interjection! "Oh my god, Ralph, that's disgusting!"
Discriminating one person from another! "Not you, Dan."
And any number of other scenarios. Whether you should use names depends on context, your characters' speaking habits, and your own style. Go with what works best for the scene. If it doesn't sound unnatural and doesn't slow down the reader, there's no reason to cut it.
Don't Wait for Inspiration, Just Write
I'm sure this one works for some people who have motivation issues. It doesn't work for me. The things I write when I'm not feeling inspired are crap. If you're a binge writer, take heart, because there are plenty more of us in the world!
What I would suggest as an alternative to this rule is (a) learn what inspires you and (b) know when you've hit a dead end. There's a difference between waiting for a perfectly formed novel to drop into your imagination, and only starting to write when you've got an idea that excites you.
As I said, though, your mileage may vary. If you get good results from forcing your fingers to the keys every day, by all means, don't quit!
Read Five Hundred Gazillion Books a Year
I'm not going to dispute the idea that in order to be a good writer, you must also read a lot. But "a lot" is relative. Book tallies can look a lot like pissing contests. Don't feel discouraged if you're a slow reader and aren't one of those people who can fly through multiple books a week. Read at a pace that's comfortable and enjoyable. Read enough to inspire yourself, refine your craft, and stay abreast of your genre. Don't read just to rack up numbers.
That's all I have at the moment! What are your favorite writing rules to break?