Glass jars and bottles are infinitely reusable, but the label doesn't always stay applicable for very long. Luckily, the cheapest method for removing the label and its sticky adhesive is also the laziest.
Photo by Roman Boed.
According to Food52, all you need is a little oil (literally any oil; even mayonnaise works),some warm water, and a scouring pad. Just smear a bit of the the oil on the label, submerge the jar or bottle in some warm water, and leave it over night. Remove your glassware from the bath the next morning, and scrub the label off with a scouring pad. Wash with a little soap and water, and fill your clean, label-free receptacle with whatever you desire.