I'm a Scoutmaster, and I have 5 kids, so when I go camping it's about speed and ease of cleanup.
First... have a way to make lots of hot water fast. We make hot water in a big tea kettle or in an enamel pot on a big Camp Chef stove. When we're all done eating the hot water in the enamel pot makes cleanup go a lot faster.
I also think of ways to use the hot water for "instant" food... hot cocoa, oatmeal, rice, ramen, etc... it can really speed up cleanup as well. I also think of ways to use prepackaged food in unique ways... boil water, bag of egg noodles, drain most of the water, 2 cans of canned chicken, can of cream of chicken soup, can of cream of celery soup, can of sliced mushroom, black pepper and a dash of hot sauce makes a great chicken stew. If you have an extra burner and skillet, sautee some onions while the water is coming to a boil and add with the other ingredients for more flavor. (OK, that's a big recipe, cut in half is easily four regular servings.)
Second... think of ways to do kitchen prep at home, or have things already cooked (and maybe frozen)... slice and dice, precook meat and freeze (uses less ice that way). Cooking bacon to "almost done" at home helps answer the question, what do I do with all this bacon grease? Boiled eggs - then it doesn't matter then if they break in transit. Egg salad sandwiches is a great alternative to cold cuts for lunch, or you can cook them while your cooking breakfast and it's a no-cook lunch.
Third... coleman stoves are good for a couple or two, but when the group gets bigger, bigger burners and a big cast iron griddle REALLY speeds up the food production. Our troop has a three burner Camp Chef stove... if you have the room and need the production rate, there's simply no substitute. We also have a dedicated ~30"x24" propane griddle with a thick stainless steel cooking surface, ~3/8" thick - yeah, it's real heavy but it's the bomb for pancakes and scrambled eggs when more than a small group.
If you have electric, there's no subtistute for an electric griddle for pancakes, french toast, scrambled eggs, bacon.
Fourth... A "tabletop" propane grill is one of my favorites. More even heat for a the cast iron griddle, roast corn still in the husk, make burgers, chops, and dogs, even foil dinners. With the griddle we also make tuna melts, rueben sandwiches, or whatever toasty meat sandwich you like.
But sometimes "old school" with a small pile of coals from the campfire and an iron skillet is the way to go.
I'm also on the lookout for a big cast iron cauldron for making kettle corn. Right now I make it in my Whirly Pop, but cleanup is a mess with all that melted carmelized sugar.