At the end of the school year send a few post cards with stamps home with each student and ask them to mail them to you when they have finished a book. Students could also send postcards to students in the same grade but at a different school and tell them about a book they finished,
These free printable prayer postcards are a great way to tell someone that you are praying for them! They have space for a short note, encouraging verse or a picture by your kids. Free 2-sided printable to download.