I'm sure you've all heard it: "Get out there and build your author platform before you are published!"
In moderation, this might even be a reasonably good idea. But here are the two places where it goes wrong:
1. The most obvious is that writers suddenly give up writing for marketing, and give marketing far too much attention when they should be focusing on their novels and writing the best story they can. Great; they create website, blog, FaceBook, Twitter account and they leap in. This delays the writing process because most people only have so much time they can devote to this business.
2. Now you are one of thousands of other authors (or would-be authors, since many of you don't have anything out yet) who are listing all the things writers should and shouldn't do. This is a favorite type of post. Do you really think people are paying attention? You're getting lost in the crowd of the four dozen other Tweets every hour about blog posts on writing. People are no longer reading them and you've now failed at both marketing and writing, which you should have been doing in the first place.
So, what do you do instead?
Write. Blog/Tweet/whatever about your own writing when you have something cool to share. Talk about what you have learned as it pertains to your specific book. Don't parrot all the other sites out there and list out the rules of what you should and shouldn't do unless you actually have some experience in it.
Go finish your book. Go submit it or publish it. Market the book and not yourself as an all-knowing author, because none of us are. What works for me will not work for you. For every 'Don't do this' someone is going to prove the 'rule' wrong. You may not like the result, but they'll make it work for them.
Also don't spend all your time just pushing your book. You are more than your writing. People who only Tweet with links to where people can buy a book are going to lose followers. It's boring. Get some of yourself out there. Join in conversations with others on Twitter (or wherever) and show people you are a person, not just a bot dropping in a link.
So why am I doing the exact thing I'm saying not to do and making a list about what authors shouldn't be doing? I'm not an unpublished author, even though I'm not a well-known one. I've had books, short stories and articles published since 1998, mostly in small press. I should have been better at marketing and I'm still looking for the better results. I'm still experimenting.
And I'm listening to what I hear from others, many of whom are readers, not writers. The big thing I've heard lately is that people are just tired of being lectured to by writers who have not even finished their first book. They want to see personality and something that makes them interested in the upcoming book.
This isn't easy, but the best advice I can give is to not follow the crowd. Be yourself. Be creative. Spread as far and wide as you are comfortable with in marketing without losing track of your real goal.
And no matter what else you do, have fun.