Each child gets a name tag to wear around their neck. Throughout the day the children get stickers on their name badge for every “please, thank you, excuse me, etc… Whoever has the most stickers on their badge by the end of the day wins a special prize!
I use a small card file box and call it a treasure box. In the box I place the foil wrapped chocolate coins. To play, the first child says “please pass the treasure box” when the child holding the box hands it to them they say “thank you” and the other child says “your welcome”. I don’t remember where I originally got this idea, but the children do love it. You could vary it by the items you put in your box.
Play the old standard “Mother May I” game with a little manners twist. Have the children say “Mother may I…. please” and “Thank you”. Game caller says “Yes you may” and “You’re welcome”.