This is an example that I've used with my students to help them right more meaningful thank you cards to community members that have helped or donated to our class.
There are 2 different sets of instructions.
In set 1: Chicken Thank You Cards
We had a farmer donate fertile eggs for our class to hatch and study. We measured feather lengths and bird weights for 3 weeks to learn how the babies developed.
In set 2: Oxley Thank You Cards
We went on a field trip to a nature preserve. We had 7-10 docent volunteers that came out and led small groups of students on nature walks into the woods.
Feel free to use these instructions to modify for your own situations in your classroom. My classroom is a high school classroom, but thank you cards are universal for all ages!