I used to get a different card (regular sized one, not one from the typical classroom pack) for the teacher. You don't need to do more than that, but I used to include a $10 Starbucks giftcard or something like that.

I don’t do V day gift for teacher - just the cards for the kids.

They say that kids have to bring valentine cards or googie bags on valentine day, and this is for 3 year old class. Should I pack some for teachers? If I should, should I pack same (paper card & a sticker) ones to teachers or a different ones (like add some chocolate or etc) but small one?