The first one is the easiest. When you cook up vegetables don't put butter or sauce on them. You can have it on the table for whoever would like some, but that doesn't mean you have to put it on your plate. Like I said, it's an easy one.
Next one is similar to the first one. When you bake casseroles or similar dishes that call for cheese and sauces on top, don't put the toppings on a smallish section. That way you have some with out the calories heavy toppings and can top it with your own lower calorie toppings. Another twist would be to leave the toppings off completely and just have them on the table for everyone to add to their plate.
There's a few substitutions you could make in the recipe that would help bring down the calorie and sodium content without anyone realizing it. A quick google search would probably give you way more options that I could ever think of, but a couple t get you started would be switching out ground turkey for ground beef or pork. Or cutting down on the meat in the recipe and adding in extra beans or vegetables. Or simply switching to the lower calorie/sodium version of ingredients in the recipe. A lot of the seasoning mixes, like taco, chili and fajita seasonings, come in a lower sodium version. If they are open to it, you can try to get your family (or friends) to try out the light versions of things like mayo, salad dressings or cheese. My husband actually seems to prefer Diet Dr. Pepper and the light Hidden Valley Ranch. It might not be quite as good as the original, but I'm sure that after a while their taste buds will adjust to the new flavor.
Now, I wouldn't suggest trying to change everything on them all at once. Maybe make one change a week to ease them into the healther way of eating. It's possible that they may eventually prefer the healthier way of eating, they might just need to be introduced to it.
Had to include a nummy food picture, it is a food blog afterall :-)