Where do you go to get Double Boxing Services?

Was looking to find out where/how people handle boxing and double boxing. A couple of a components I plan to list for sale were bought back when I didn't think I needed the original boxes. Now, I want to sell them, but was wondering about where people go to get them boxed. I live in West Los Angeles, but I'm sure anyone could have a good idea or two on how to handle things properly for our buyers!