Using empty boxes, bags, bottles, etc. to fill with garbage before actually throwing them (and the garbage) away, rather than recycling them and waiting for them to be reincarnated as a box, bag, or bottle made from recycled goods.
Clerk: "Would you like a bag?"
Customer: "Yes please. I don't really need it to carry this stuff, but I'll be precycling it because my bathroom trash can is full and consequently needs a new liner."
Clerk: "How very clever of you. Is that really a word?"
Customer: "Urban Dictionary thinks so, so... yes."