Sometimes it helps to keep in mind some basic facts. Sentences are machines. Machines have parts. There are three basic parts to a sentence, subject, verb, and object. For example, “I walk to the store.” I is the subject; the verb is walk; the object is to the store. Go through your writing and identify each of the three parts. If you are missing a part that isn’t good, and if you got too many parts that might not be good either.
That’s it. Over and over, and over again, just keep doing that in interesting ways for the next 60k and you’ll be good to go. There are a couple other grammatical parts. Nuts and bolts we can call em. I’m talking about things likes commas, colons, semicolons, those sorts of annoying things. The rules are simple. Most of the time avoid them, unless they serve a critical purpose.
Small parts, like commas, are deceptively simple. The idea is two independent clauses, which have both a subject and predicate, are separated by periods. Commas are used when you are using a dependent clause, which is attached to the independent clause. So for example, “I walked to the store, for milk.” is a proper use of of comma. The “for milk” being the dependent clause, I think?
Semicolons, these buggers are tricky. I recently read an excellent article on semicolons which I will leave at the bottom for you for better explanation. But in my own words, a semicolon is the exception to the rule on the commas use. One way semicolons are used is in lists with internal punctuation. For example, “I had three friends over for dinner, Frank who I knew since childhood; Andy, my neighbor; and Carol, from First Presbyterian Church.”
The other way is more interesting and hard to always get right. Periods are full stops; Semicolons are like half stops; and commas are quarter stops. Semicolons strangely can hook up independent clauses, but again they are like commas in that they refer to the first independent clause, for example, “He went to the store; he had not eaten for days”. Overall, Simplicity is is advised though. Subject/predicate. Subject/Verb/ Object.
I really battle with these things and have to constantly remind myself and pay attention to the writing. Keeping it simple will move you along faster. Let go of cluttered sentences and reduce them to simple sentences. Keep it short and descriptive. Let the elements, the simple parts of the machine, work for you.