By Lisa Trottier

In a country that likes its portions supersized, airlines have been drastically downsizing meals. While most of us have fallen back on airport food—Big Macs and pizza slices—some savvy travelers are assembling Martha Stewart-worthy picnics at home to take on board the plane.

"If you don't want Taco Bell, you need to plan ahead," says Kathryn Jessup, a UC-Berkeley graduate student. Jessup's preflight routine involves shopping, at-home preparation, and careful packing ("lots of Ziplocs and deli containers"). For a short flight, she takes sushi. "And cucumber and jicama slices for crudités. And sliced watermelon. And something salty like picholine olives."

A spread like that doesn't go unnoticed by other passengers: "I do feel eyes on me when I pull out an elegant little box of Michael Recchiuti chocolates," Jessup says.

And conflicts can arise over smells. "Fish products create certain odors," is how Terry Sousoures, vice president of the San Francisco chapter of the Association of Flight Attendants, diplomatically puts it. Then there's the mess. Sousoures says passengers are leaving behind more trash.

Fear not if you've never packed a picnic to consume at 30,000 feet. Amanda Hesser, who has written about her elaborate in-flight meals in The New York Times and in her book Cooking for Mr. Latte, offers these tips:

• Sandwiches made with cured meats like prosciutto hold up better than those filled with chicken salad or tuna salad.
• Pickled vegetables travel better than salad.
• Foods you can pick up with a fork or hands are best. Avoid foods that need cutting.
• For dessert, chocolates or soft cookies make a compact treat. Pack extras to share.
• Bring a large bottle of water—you never get enough in coach.
• Bring a plastic bag to hold your garbage.