In our school the kids bring a valentine card for everyone in the class and the teacher has the kids create an bag or some type of holder decorated for the special day.  Some teachers can create a whole week of fun activities for the kids celebrating giving and inclusion.

Each card is given out an the kids come home with a set of cards from their class. No one is left out.  Each family can decide if the cards are home made, store bought or include a small candy (or not.) 

I have some great creative ideas and tips for making cards for the classroom if you need some inspiration.