This is the largest part of the writing process that I struggle with. I do not know the best references for style or for learning how to get better with the grammar but I am always on the lookout for ways to improve. I was recently told about grammarly and Hemingway as sites and applications that I can use to help find the grammar issues with my manuscripts. Sadly I know that there will be a large number of errors found when I get to that point.
It has been pointed out to me from editors I have worked with in the past that I tend to overuse the word "and" and well as commas. I also for some unknown reason struggle to use wonder and wander at the right places. I always seem to mix them up even though I know how to spell each and what they mean. No matter how much I focus when I am writing I always find these issues and they are the first items I look for when I start my editing.
Formating is another issue that I am learning and in many senses that also has to do with grammar and style. The ability to create sentences that flow and have the correct layout is a priority though with dialogue authors do have some latitude to move around. People aurally speak with proper grammar. Even if they do, when you read it the dialogue sounds forced and overly proper. Slang accounts for such a large part of the way we speak while at the same time wreaks havoc on the grammar check for any computer.
I do own the Chicago Manual of Style though I would be hard pressed to admit to opening it more than a few times each year. I used it more when I was in college. It is a good reference but I have always liked books more about finding a plot or developing characters that are relatable if not always likable. I am intending on taking a few English classes in time that will allow me to improve my skills for writing overall especially the grammar but I welcome any suggestions that recurrently out there and will be offering how much I like Hemingway and grammarly as I get the chance to use them.