Last week I was on a writing course in Oxford. It was How to edit your own women's fiction given by Julie Cohen and Helen Corner.
In three days I learnt so many things it will take me some time to wrap my head around it, but the most important advice I came home with was to always ask yourself WHY. You should write as if you had a nagging little four year old sitting on your shoulder and asking Why about every single word in your manuscript. This will give depth and credibility to your plot and characters.
During this course we had the chance to look at each other's work, and as we analysed mine, I realized I didn't know my characters properly. I hadn't understood or considered their background enough to determine why they followed one path or another, so I hadn't been able to form round live characters that would engage the reader.
Also, I've learnt many of the basics I needed (e.g. pacing, show and not tell) to feel more confident about what I'm doing. This means, I feel ready to dig deep into my story until I find the treasure I was looking for.
Where did you get your writing knowledge from? Courses, books, blogs...? Or are you lucky enough to have been born with that knowledge.