If you are looking for a Valentine bag idea for upper elementary, I made this fun bag activity, and it can be found in my TpT store. It lets students share a little about themselves, and it also has a book report sheet the kids fill out and glue to the back. They get to share about a book they LOVE. After they bring it to school and present to the class, they get to fill it with all of the Valentine cards their friends brought them. Even big kids love Valentine's Day activities. It's one of my favorite days of the school year. :-)
Find the Printable activity in my TpT store.