Many store-bought food items come in reusable containers, but we tend to just throw them into the recycling bin, or worse yet, the garbage can. Even recycling, while better than throwing away, is wasteful. It takes energy to recycle the raw materials, and if you buy storage containers, you have lots of waste in the manufacture, advertising, and retail of the items.
When I buy an item, I opt for a reusable container whenever possible. Rather than buying my pasta sauce in an aluminum tin, I buy it in glass jars. By shopping sales and using coupons, I can pay the same amount for the nicer brands in a glass jar as the aluminum tin of store brand. I also use wine/whiskey bottles with a screw top, pepperoncini/pickle jars, or condiment bottles.
Clean them out very well before using. Soak in warm water for awhile so you can scrub off the label, if desired. Scrub the inside and outside and take pains to clean every last bit of food from the lid to avoid mold. Sometimes a bit of scent remains if the jar is from a strong-tasting food such as pickles or salsa, so I take this into consideration when filling the jars with bulk-purchased or home-made food items. For example, I don't store loose leaf tea in a pickle jar or sugar in a tomato sauce jar. I will, however, store rice, TVP, or beans in the more strongly scented jars. These items are not negatively affected by the scent, but absorb the smell so I can use it for something else in the future.
Tiny glass jars are great for spices. I was once given a tiny 2 ounce sample jar of peanut butter spread. This jar is the perfect size to store a frequently used spice near the stove for easy access. A fun space saving idea is to save baby food jars with metal lids. Screw the lids onto the bottom a cabinet. Fill the jars with spices and screw in. Your spices will be easily accessed while you cook, and don't take up any valuable counter space.
I once found a bottle of salad dressing with a spritz top at a bargain price. I cleaned it out very well, then refilled it with olive oil. When I pop popcorn in my air popper, I can spritz a small amount of heart-healthy olive oil onto it, rather than dousing it in butter, or pouring on too much oil. Any condiment bottle with a thin neck and a screw top can be used for homemade dressings and sauces.
When I buy cream cheese, it is the same cost to buy it in a plastic container as it is to buy it in a little box. These containers are the perfect size to freeze an individual portion of soup. This makes packing lunch for work a breeze.
An old wild-mouth jar stores bacon grease in the refrigerator to add a bit of flavor to cooking.
Wine bottles make excellent vases.
A collection of bottles of various sizes and shapes can make for a nice country decor. Fill with foods of different shapes and colors: veggie pasta, beans, TVP, rice, etc.