Be careful with your commas. The majority of people use too many. You need a comma when you have multiple prepositional phrases in a row, when you have a dependent clause joined to an independent clause, when you have two independent clauses joined with an “and,” and when you have a list. That’s pretty much it. Before you comma, justify why you need one before you hit the button. If you’re not sure, google it. Even editors do that.
Minimize your punctuation, especially when it comes to ellipses, em dashes (the long dash), semicolons, colons, and exclamation points (one of each per page max). Only italicize internal monologue and eliminate underlined word and words in all caps.
Mix up your sentence structure, or your readers will fall asleep. I.e. Short, short, long, short, compound, short.
Minimize “dialogue tags” (he said, she said) in favor of “dialogue beats”. These are physical actions that denote who is doing the speaking. “Why’d you do it?” Rachel’s eyes squinted as she glared at Timothy from across the room.
It‘s not necessary to tell your audience who is speaking every time, especially if there are only two people in the conversation.
The difference between ‘that’ and ‘which’ – four out of five times, ‘that’ should be used. If you’re writing a clause that is nonessential to your sentence, use ‘which’.
Be open to suggestions and fierce editing. For the good of your work. A good editor or critique group will care as much about the work as you do, and their job is to draw good writing out of you. Editing is a conversation, to provide another perspective. Authors edit as authors, but editors edit as readers.