All the mechanics of writing are part of the craft. This is the stuff you can learn to make it so all readers can understand your writing and so your style contributes to the overall experience of your story. This might be the stuff that editors take care of, but editors are not responsible for all of it. Writers are.

Vocab & Diction or Word Choice

Read the dictionaryReading a lot of stories and nonfiction content can help improve your vocab and spelling. If you have a real problem with basic words, search online for spelling games or quizzes to take, or peruse a dictionary or "Word of the Day" sites. Understanding prefixes, suffixes, and root words can also help construct words more easily.

Writing is not about using the fanciest word, but if you do pull one out, you need to spell it correctly. Spell check can only go so far. Also, understand the nuances of meaning that some words carry. Some have positive or negative connotations that could make your sentences seem odd if you ignore them.

Words are, after all, the material with which we create. If a potter doesn't know clay, she ends up with either a dry brick she can't form or a sloppy mess flinging about the room. We don't want our books to be dry bricks or sloppy messes, right? So we need to know words. Lots of 'em.

Writing Basics

Basic understanding of parts of speech and word usage rules. This also extends to things like past, present, and future tense verbs, adjectives and adverbs and when to use them, and proper capitalization.

Punctuation can change the entire meaning of a sentence. The Oxford comma is famously used as an example in phrases like, "We invited the strippers, JFK and Stalin" vs. "We invited the strippers, JFK, and Stalin." The first sentence means that JFK and Stalin are the strippers. The second sentence means that the strippers, JFK, and Stalin are three separate entities that were invited.

Do I HAVE to know grammar and punctuation? Isn't that the editor's job?

Yes. No.

A plumber needs to know how water flow works in order to lay pipe the right way. A doctor needs to know anatomy and physiology before she can do surgery or prescribe the right medication. A baseball player needs to know how to run fast, swing the bat, and catch a ball before he can play a winning game.

You are a writer. You need to know how to write -- not just tell a good story. Writing requires grammar, punctuation, spelling, word choice, flow, pacing, etc.

Yes, editors absolutely help with this stuff. A good editor is awesome. However, if you do not even make an effort to use your language of choice well, you cannot call yourself a quality writer. I know this sounds judgemental, but I firmly believe it is true. Besides, don't you want to be the best writer you can be? There are no shortcuts.

Literary Devices

These are the fancy things like metaphors and alliteration that can either make your fiction writing unique and expressive or bogged down in so much purple prose that your reader may be compelled to stare at a blank wall for an hour or two after reading to give their mind enough time to clear out from all the mess.

There are reasons to use a lot of these things in the story, but, in my opinion, it can be difficult to teach where it should happen and where it should not. Some things like alliteration (Starting many words in a sentence with the same letter sound) or onomatopoeia (Writing out sound words like boom and pop) align more with a whimsical or lighthearted subject matter. Others like foreshadowing, literary irony, and metaphor are frequently used in many different types of stories.

You should develop an ear or eye for it the more you read, learn, and write. If you don't, and you still can't figure out how to use them, you can leave them out and still write a story. They add color, flavor, and emotion to writing, though, and these are important things if you want a really great,  can-not-put-it-down type experience for your readers.