How to be Insulting on the Beach: Try to find seaweed and drag this along the beach, leaving bits beside other people's places.
How to be Insulting in Church: If you just want to look inside the church, go in when you see the sign 'Service in Progress'. Take photographs with a bright flash-gun.
How to be Insulting in Church: Pour water into the font and wash your hands in it. If you're really daring, take off your shoes and socks and cool your feet.
How to be Insulting on the Beach: If there's enough sand, dig huge walls around your site and try to put your neighbors in the shade.
How to be Insulting at Christmas: Buy crackers without any little gifts inside. If you have the time beforehand, put unpleasant little remarks and observations inside them instead. You might try to glue the paper hats together so that they tear when the guests try to open them.