One of the lowest of hanging fruit are all those plastic bags and plastic storage containers.
Glass is naturally food-safe, one of the most easily recycled materials and is also widely available -- jars and bottles can be had for pennies at thrift stores. Much of the food you buy comes in a completely reusable glass container.
I re-use glass in my fridge, my pantry, and my spice drawer. I like the eclectic look it gives my kitchen.
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