Comma Problem

So many comma errors are seen in writing today. I wouldn't be surprised to look at one of my NaNoWriMo novels and find a comma error.

Commas are sometimes unnecessarily added, or left out. Some people use them for the purpose of "emphasizing".

But I recently got a little more acquainted with the rules of commas, and I'm here to help you familiarize yourself with them. These are the rules:

• Commas must set off long introductory prepositional phrases. For example: Throughout the day and night, birds continued to die. If I had left out the comma, the sentence may seem like it's talking about "day and night birds". Also, it makes the sentence seem like a compound sentence with a gramatical error (an incomplete sentence, "Throughout the day"). Read it without the comma, and you'll see what I mean.
• Commas must follow introductory adverb clauses. A comma must separate the two. For example: As the air grew hotter, Mike felt more and more tired. This is correct. If you take out the comma, it is incorrect. Another example: If this sentence has an introductory adverb phrase, it has a comma following that adverb phrase.
• Commas must be placed before coordinating conjunctions that split a compound sentence, unless the clauses are short and related. For example, The crew threw everything overboard, but the vessel still sank. That is correct. Again, if the clauses are short and related, no comma is needed. The bomb was lit and the house exploded. That is correct. But otherwise, include a comma before the conjunction.
• Commas must split three or more items. This does not include verbs, but things like lists (Beds, tables, picture frames, lamps, chairs, and sofas littered the junkyard) and compound sentences (The dust bowl approached, Ron screamed, and the dog ran away).
• Commas must separate descriptive adjectives. The long, narrow board cracked. This is correct. Any descriptive adjectives neighboring each other are separated by commas.
• Commas must separate direct quotations unless other punctation is present. "We'll be dead in five hours if we can't get free," Ethan said. You should already know this rule.
• Commas must separate nonrestrictive adjective clauses. This sentence uses a nonrestrictive adjective clause: The five-legged wolf, who had just walked five hundred miles, was finally at the required location. This sentence uses a restrictive adjective clause, meaning no commas are needed to separate it: The wolf who had five legs was finally at the required location.
• Commas must set off interrupted parts of sentences, like appositives, nouns of direct address, and parenthetical elements. Appositive "Thomas's neighbor": Harry, Thomas's neighbor, was indeed the thief. Noun of direct address "Britain": After all, you set the bomb, Britain. Parenthetical element "as everyone had expected": The weather, as everyone had expected, was cold.
• Commas follow mild interjections and other introductory words at the beginning of sentences. Mild interjections like well, so, and say are typically placed at the beginning of a sentence; therefore, they are set off by commas. This also goes for other introductory words, like yes and no.
• Commas separate digits of numbers every three digits and parts of dates and addresses. They also follow greetings of non-business letters and after closings of all letters. You should know most of this. Especially the number-comma rule.