Mmm, picnics..
I love the idea of doing a turkey and swiss wrap, with alfalfa sprouts, mayo, and tomatoes.
Some fruit, like grapes are nice and a bottle of wine.
Homemade brownies or oatmeal cookies would be delicious too, afterwards.
Must-haves include:
Thick blanket or comforter (an old one, because it will spend most of the time on grass or dirt)
Food
Drinks (cold water, fruit juice, or soda)
Ice (don't bring perishable foods if they can't be kept in a cooler)
Drinking cups
Eating utensils
Serving utensils
Napkins/paper towels
Salt and pepper
Condiments
Trash bags for cleanup
Sunscreen
Hope you have a blast!