I drive around town and look in dumpsters.. not for trash, for cardboard boxes not too far in, that don’t have trash or foodstuff on them, take them home, re-assemble them into box-shape with some tape, and use them to ship the things I sell on ebay. Free publications around town of various types (GreenSheet is one locally, another is a spanish one) can be balled up into small balls. Fill the empty spaces in the boxes with balled up paper. Keeps costs down for selling online. IYAMCHEAP.