Every Friday, the students in my classroom write a letter to their parents about their week in class in their Friday Journals.
The students then take them home over the weekend and I ask that the parents write a letter in response to their child. It's a great remedy for the question, "what did you learn in school today?" I also love seeing the interaction between the child and parent.
If the students bring their Friday Journal back on Monday with a parent response, they receive a sticker on the cover of their journal. By the end of the year, the cover looks really cool and the parents have a special keepsake!
I spruced up the parent letter a bit for you and you can download it for free here.