Tupperware-style containers are not your best choice for freezing; they allow air into foods, therefore moisture, which leads to more freezer burn, and faster, which makes food go bad much sooner. Also, the cold of a freezer will make plastic much more brittle to the point that it will break much more easily. For most meats, I unwrap the plastic (carefully, so it doesn't tear), remove the plastic tray, and then rewrap the plastic. That gets rids of the air space that leads to the meat going bad so much faster.
I wrap cooked freezer foods in plastic in one-person servings (for larger families, wrap in packages of whatever size you will use at one time), the put the wrapped items in labeled freezer bags - those can be reused later because they never actually touch the food. For soups and stews, or any prepared foods with a high moisture content, I line an aluminum container with plastic wrap, fill the container 3/4 of the way full, fold the plastic down, and then put the lid on it. Once the food is solidly frozen, I remove it from the container and package as above. I like the small loaf-pan size aluminum containers because I have a stack of similarly-sized plastic containers, so when I take things for lunch, I can put a wrapped item in the plastic container - by lunchtime it has defrosted enough to remove the wrap, and then I can heat it in the microwave.
