The Proofreader's Eye: Spotting Common Grammatical Pitfalls

Hi everyone.

As I take on more editing responsibilities, I am looking to improve my ability to catch subtle mistakes that automated tools often miss.

The deeper I look into the rules regarding punctuation marks and uses, the more I realize how frequently I used to overlook the correct placement of commas in complex sentences.

I am currently putting together a cheat sheet of common errors to help my team refine their draft documents.

What are the most frequent punctuation mistakes you encounter in professional submissions, ¿and how do you quickly train your eye to catch them during the editing process?

Thanks in advance.