I'm finally letting go with my boxes. I have tons of larger sets, UCS SW, modulars, Death Star etc. They are all flattened except for DS, HP hogwarts and UCS MiLF. Before I list them to sell, if someone is interested in buying them, how does one go about pack them up to ship? I'm not trying to make a lot of money off of them but I just can't wrap my head around bringing flattened boxes to the USPS and asking them to ship them since I doubt they make boxes in these sizes. I have a few old Lego/Amazon boxes that might be able to pack a few, but not many. I just want to know how it's done before recycling day next week. Thanks for any insight.