The most common mistakes for high school students' writing is their lack of knowledge of the advanced punctuation. Yes, most of them can use a period and a question mark, but many misuse commas, semicolons, colons, dashes, and hyphens--all punctuation marks that (when used correctly) can add voice to our writing and really advance the writing as far as punctuation and grammar.
This document includes individual posters that could be printed and hung in the classroom along with condensed versions that can be printed and given to each student as a quick reference guide to the rules of those misused punctuation marks. Fun, funny, and engaging examples are included for each one, and some of them even point out other grammar related items, such as independent clauses and dependent clauses. On the last page is a list of all the CCSS that these printable cover.
I hope you--and your students--enjoy!