I use ziplock bags a lot in the freezer - they take up less space than plastic containers. The bags labeled "freezer bags" are thicker and better for freezing than those labeled "storage bags".
Some things that freeze well:
*Mashed white potatoes and sweet potatoes (white potatoes separate in the freezer, but if you microwave them and stir a couple of times, they come together fine)
*Whole milk, skim milk (shake after defrosting). Cream and buttermilk - not so well.
*Muffins, scones, any bread, cakes, cookies, fruit pies
*Casseroles. I usually cook before freezing, but you can freeze them uncooked as well.
*Soups, chili, stews. I omit potatoes and pasta from soups, and add them when reheating.
*I stock up on chicken and meat when it's on sale. I usually repackage it into the amount for one meal and wrap in plastic wrap, then foil.
*Be sure to leave some head room - 1/2 inch or more - when freezing liquid (like soup, milk, etc.) because liquids expand when frozen.
*Blueberries, blackberries and cranberries freeze well. Put them on a cookie sheet and flash-freeze; when frozen, put in a freezer bag. This keeps the fruit separate; it won't clump up and you can remove just as much as you need. I put them frozen into cobblers and muffins.