For instance I re-use elastics and bread tabs as well as plastic bags. I think I've only ever bought elastics once in my life.
Now that I make a lot of my own bread I'm re-using the bread tabs for my own bread bags, and for any bag that I want to keep closed. I also saw another purpose for bread tabs in a recent blog post - they make great tags for labeling all those wires behind your computer and TV.
I also have a stash of empty plastic gum containers which I'm trying to figure out a use for before they go into the recycle bin.