You can make them before you go or just bring along the bread and fillings and everyone can build their own masterpiece. A great tip for picnics is to wrap sandwiches and wraps securely in paper or pretty serviettes and label with the contents or the guests name and, if you want to add an extra touch , tie with string. You can also use toothpicks to hold sandwiches or the bread sushi together.
Salads are perfect for picnics. Try more substantial ones that are easier to transport like potato salad that includes some chopped up boiled eggs or a delicious pasta salad with tomatoes, olives and a pesto dressing.