Commas can be quite confusing. Young writers target troublesome grammar skills by focusing on the four most troubling uses: joining two independent clauses, separating introductory materials in a sentence, separating unnecessary information in a sentence, and separating items in a series. A short discussion of when to use a comma precedes a mini-lesson that uses sentence strips inscribed with parts of model sentences. During guided practice, the sentence strips are arranged on the board in a logical order. Volunteers fill in the missing punctuation and coordinating conjunctions while reinforcing proper use of commas. Following up with the revision of a prior writing assignment is the most effective manner to move comma rules into long-term memory storage.