The positive point about longevity is that with any group, trust and closeness grow over time, and this genuine caring among students does nurture the work. Sometimes, for instance, it's good to repeat an exercise focusing on verbs, a reminder about the importance of active verbs over passive verbs. You could repeat the same exercise over and over and each time the results would be new. For instance, you could write on the topic food over and over, and never be finished with it. You may write five times a week with different classes on the same or similar topic; each of your writings will be fresh, usually better than the last. Don't be bored with repetition.
Emphasize content while correcting form. "This is a great idea. Now, let's notice that the first word of a new para graph is indented. We capitalize proper names and "I" as a name. Capitalize names; do not capitalize other words. Capitalize the first word in a sentence. Sentences end with punctuation, usually a period."
Common mistakes lessen and fall away--"a lot" becomes two words. Students begin to use common homonyms correctly--their, there, they're and to, too, and two, hear and here. Play a game with students: "How many pairs or groups of words can you think of that sound alike, but are spelled differently and have different meanings?" Weigh, way--rain, reign--through, threw--bored, board--fore, four--hair, hare--pair, pare.