Print work out on paper and edit on paper before sending out anywhere.
It’s easy to miss things on screen. Printing out acts as a useful double check. And it’s easier to see how your work “looks”. I use the reverse side of these drafts for scrap paper and often use it to scribble my next novel.
Don’t rely on the computer spell and grammar check solely.
Always use a good dictionary/grammar guide as well. The computer doesn’t always get it right! Mine seems to have an aversion to the word “their”, it keeps saying I should use “his or her”! Imagine how clunky that would sound in a story! See the computer checks as a starting guide only. I use the Concise Oxford Dictionary and Thesaurus.
Make sure you know your character well enough to be able to write about them.
Or you’ll have no story! Or you’ll quickly reach a dead end. Some writers do a full character CV. I tend not to but do start with a main trait and take things from there. For example in Eileen’s case, I gave her the traits of awkwardness and defiance. Loads of stories can come from that!
Enjoy your writing!
Or there’s no point to doing it at all, is there? Also I think if you love what you write, it will show in what you write and make it a more enjoyable read and therefore a more publishable one.