No one from either UPS or FedEx has ever asked me what was inside, they just basically let me drop off the package and move on. The answer I always have prepared just in case is "food samples for analysis", but on second thought that's probably still a little suspicious. How about "non-perishable food in glass containers". Now that's being honest without being suspicious!
I always leave out any reference to "beer" in the address.
For example, Craft Beer Cellars becomes Craft Cellars, New England Regional Homebrew Competition becomes NERHBC, etc.
The folks at the local UPS drop-off location don't ask, I don't tell.
Great points -- I began doing this as well in recent history.
I don't even say that I have glass containers. That raises more suspicion. I think that we all pack our boxes well enough that they can be dropped off the Empire State Builiding. I think I just shipped 7 bottles in a box that was 24"x16"x10 (round about). It was loaded with bubble wrap and paper packing. Yeah, I even though it was a bit crazy over kill. Yeah, the one I got in the mail in return, was just about the same size. I don't even say the package is fragile. I really don't think it makes a difference.