Re purposing office supplies is a great idea.

We use old paper as scrap paper.

sounds good, also for a while I was bringing home plastic containers from my job. (I work in a bakery within a supermarket and we had empty plastic containers from samples.) Instead of tossing them in the trash I brought them to my house to be collected in the yellow bin; we also have a bottle room and plastic bag bins. I noticed many stores not just grocery stores collect plastic bags.