I pre-cook as much as I can. I'm lazy at the end of the day and the last thing I want to do is mess up my clean kitchen and slave over a hot stove for hours!
The best freezer staple is pre-cooked ground beef. I make about 10 lbs at a time. Just brown with a little salt, pepper, onion and green pepper. I use this for anything Mexican, hamburger helper, spaghetti and other Italian dishes, sloppy joes, etc., basically anything you'd cook up fresh GB for.
Another time-saver is cooking double and freezing the rest. This is really easy with large pieces of meat, like whole turkeys, roasts, etc., as well as Italian dishes like lasagna. Even making an extra roasted chicken makes getting dinner on the table faster.
Sometimes just having an entree on hand makes dinner easy. My DH likes to smoke meat and we have a nice stock of smoked brisket, chicken and ribs, all ready for an instant dinner. I just add a couple of easy sides like baked potato salad, cole slaw, beans or pasta salad. Even my DD4 likes these dinners!
Another tip is to freeze leftovers in taste-specific freezer bags. I have one for Italian, one for Mexican and another for chicken. Leftover beef roast and pork products usually land in the Mexican bag, and broth from canned veggies goes in the chicken bag. Kind of like garbage soup, but without too many mixed flavors. These turn out really well, and are amazingly easy to use. The Mexican and Italian usually end up as Mystery Casseroles, and the chicken one gets turned into soup.
Thinking about what is available in convenience foods in grocer's freezer section will help you find recipes that freeze well. For example, take pre-cooked hamburger patties. While not particularly appealing, I do have some waiting in my freezer (homemade of course). The last time my DH fired up the grill for steak night, he cooked 8 hamburger patties just for the freezer. Cold fried chicken discounted at your grocery's deli also keeps well in the freezer.