I save (and use in my art) glue dots and tape. Glue dots or bugger glue as I recently heard it called comes on all kinds of things; cards, meat trays. I removing it from its source and sticking it on wax like paper for reuse in the future. I use it just like glue or tape. Love old tape also. Hehe, I have a tape wall. I take the used tape and if it still has tack apply it to my tape wall. I have stuck it on a board before for easy portability and convenience. Reference the tape wall when you need a piece. I have a wide variety of different types and colors all because I am sourcing it.
So I have a love/hate relationship with plastic bags. Okay I really just hate them but they are everywhere and are very useful. I have a box dedicated for used plastic bags, clean of course. Most products come in plastic, look how the bag opens. Open carefully or cut a clean edge if it tears. I like the soft plastic the best as opposed to the crinkly kind. I keep all sizes and store artwork in them, give work safely to customers or even use as a gluing surface. Works perfectly after gluing to keep the area clean and will not stick or damage areas if glue seeps out. Once you start looking for the bags they are everywhere. Designating a box to store them in, keeps it organized and easily accessible.