I include a Xerox'ed copy of the destination FFL in the box, mainly in case the shipping label is defaced there's a fighting chance (alright, slim chance) it'll end up getting there. I have an FFL (C&R, because I only mess with old stuff anymore) and am happy to receive electronic copies of destination FFL's and conversely prefer to send my copy electronically too.
One thing I do avoid doing is putting "gunshop" in the address, or anything that would trigger an idiot USPS clerk to get their panties twisted or a thief in the pipeline to help themselves.
