I'm currently taking a creative writing class because I'd never taken one before and was curious to see what they were like. My current conclusion is that no one can teach you how to write. Sure, they can give you pointers and you can use other people's techniques and follow their advice, but you will only ever learn from yourself really. I got where I am today by writing and while I'm nowhere near perfect, I'm comfortable enough with my writing that I can hear advice and then promptly either ignore it or adapt it for my own purposes.
For instance, we were recently talking about characters and getting to know them. I've read before about character sheets and while I can't deny that I've ever used them, I've never found them helpful. Many, many, many writing "how-to"s will tell you to get to know your characters inside out. Write down all their likes and dislikes, their relationships with their family, everything about them, even if that information never makes it into the story.
Personally, I find that sort of thing to be rather pointless.
Getting to know your characters is vital, sure. It's important to know what your character feels about things. However, I've never been one to outline and so very often, my method for character development is to take a character and throw them into the situation in my story and see what they do. Every character I've written that I can think of in recent memory has been written like this. My latest creations would be Bluejay and Suli from my as-of-yet unofficially titled "Bluejay Project".
I started off with basic archetypes in mind. Basically, Bluejay was fae and Suli was a plucky young heroine. Then I threw other characters in alongside them and they began to flesh out. It turns out Suli many more insecurities than I would have ever thought up just "character planning" and Bluejay is really good at avoiding the blame for things.
Plot arises from my characters' developments. I often have a vague idea about where I want the story to end up, but how they get there is often completely up in the air. Bluejay not always getting what he wants and Suli coming to grips with herself are now going to play big roles in my projected ending. I already had something like that in mind, but actually having developed the characters enough to do so, it feels so much better.
My writing style makes for a really messy first draft, but it is a first draft filled with great discovery. Even I don't know what's going to happen sometimes. It's like reading a story for the first time, except I'm the one writing. it.