You have to think about someone who you "saved." It could be a student, one of your children, a friend, a spouse...It could be a huge save---you helped them become an incredible human being through your parenting. Or, it could be a small save---you helped a student get into less trouble during the school year...You saved your husband from inflicting his daily fashion faux pas on the public...This piece could be serious or humorous.
You begin with the words, "You saved me." Then, you write from the perspective of your student, your child, your spouse. Every time their voice does not ring true, every time their voice veers off into a rut that sounds like you (as opposed to them), you will have to revise.
Of course, the further your personality is from your student's, your friend's, your spouse's, the more you have to stretch as a writer. (And, the more satisfying the piece will be once you have worked through the drafting process.)
You end with the wondering of "Who saved you?" Meaning, who saved the writer of this piece? After all, for you to have gotten to the place where you were able to save a student or a friend, you had to be saved at some point by someone.
Following is an example of one. This is one I wrote many years ago, and still occasionally tinker with. You are welcome to use it in your classroom as a model if it would help your lesson.
Ms. R. saved me. She, of the slow-moving dinosaur era, with big spots of gray hair (thanks to me!) and old lady clothes, wearing the same old lady pair of shoes over and over and over again. Why can't she be cool and get her some Chucks?
She saved me from a life of glue crimes. Snatched my bottles of glue and my glue sticks and won't give them back. Even when I crawl under her desk and try to snatch my glue back (I'm skinny as a snake and just as sneaky), she'll grab my ankles and yank me back. For an old lady, she can be quick sometimes.
Sometimes she is boring, telling us the same things so many times, my ears hurt.
"DeMarco, wake up!"
"You're never done with a piece. You might be finished for now, but you're not done."
"Just get it down!"
"DeMarco, get up." (She wants me to get up and get a drink. She's trying to get me to wake up, but I never fall for her tricks.)
"DeMarco, that's a warning."
"Pull your pants up or I'll tie them up."
Ms. R tells me I've got a warning, but she doesn't mean it most of the time, 'cause I do lots of things in class, lots of clownin', and I almost always get recess. Ms. R don't play, though, when it comes to us dissin' each other. When that happens, the room gets quiet, like a tornado is about to come. Steam comes out of her ears and her eyes get red and she breathes fire. You don't want to mess with Ms. R when she gets quiet and starts lookin' like a dragon.
She also makes us repeat things, making us say them the "right" way. Why can't she just let us say what we have to say? She knows what we're saying...
Sometimes (lots of times) she will stand behind her desk, look across the room at me and she'll act like she's choking me. She's just joking, 'cause I grin at her and she gives me the eyebrow (Ms. R can really talk with her eyebrows), but then she grins, too.
Ms. R saved me. She tells me over and over what a good writer I am, and she acts like she is gonna fall down and faint when she reads some of my stories, saying they are "gorgeous"(nobody ever told me that before) but I know she's just fakin' when she starts to fall down like that. My stories are always about my dog Yanna and her too many puppies, but Ms. R won't let me just write down my story and be done with it. She keeps pestering me with questions that go on and on. Why can't I just write my story? I'm done with it. Why is she never happy with just a paragraph?
Who saved Ms. R? Somebody older than the dinosaurs. Somebody who crawled out from under a rock. I guess I thank them, 'cause if I didn't have Ms. R in fifth grade, I'd be stuck with a teacher who really wanted to strangle me and they wouldn't be kidding around about it. I'd be stuck with a teacher who wasn't all the time getting in my face (because she cares, is what she tells us). I'd be stuck with a teacher even older than Ms. R (like that's even possible!).