In replying to this question I thought this would make a good question...
This entire site is devoted to giving people advice on their writing, there are a near infinite number of books and magazines that intend to do the same.
Personally I have an approach to writing that seems to go against a lot of the perceived wisdom (I am happy to concede this could be why I've never published anything) But I enjoy the writing and at some point I'll likely chase myself down the publishing route.
So for someone sitting at home scribbling / bashing out their first novel, having spent an age digesting pages of advice on how best to write. How much should they pay attention to what they've read. How could they determine when to take heed and when to think they should do something differently.
How do they know what to listen to and what to ignore?