Man there's some bad advice in this thread... peanut butter, baby powder, etc... may work for your nose, but not the dog's.
FOODSAVER VACUUM-SEALED BAGS!!! Double bag that shit... wear gloves so nothing gets on the exterior. BAM! The dog can't smell it... at least not in a practical application! If the dog had all day to find it in a room.... maybe? Yeah, I know.... foodsaver bags are porous. But to what extent... I don't think it's that much. If it's maybe letting a few molecules out now and then, the dog can't smell a few molecules!!
And the people I know who've done this say USPS is the only way to go. USPS needs a WARRANT to open your mail/package! FedEx/DHL/UPS, etc. don't need shit. They can open your package for any reason at any time! That's why you always hear about the busts through FedEx/UPS... can't remember the last one I heard about USPS! So, for USPS to get into your package, they have to have a reason... if you know what you're doing you can eliminate any suspicion.
Another reason you want to use USPS is because of the sheer volume of mail that comes through there! I'm not sure of specifics, but it's at least tens of times more volume than any private courier. When they're moving that much shit... they don't have the time to inspect every package (especially if it looks just like any other).
Don't use a fake name for receiver. For sender it's OK. If marijuana showed up in a package at your door, you probably have a good chance of plausible deniability if you're smart and safe. How can they prove someone else didn't send it to you randomly and try to jack you?
I have two friends who would send back and forth to each other for years this way......