Stop using the same company names/return addresses over and over again. I received many Dr.Xanax/Dr.XanaxUSA/FastDonut packs (along with many other vendors) that had the exact same addresses and companies on them over and over again so I stopped using them because of this. (Which may have been part of the cause of them getting caught) Switch every week and if you can hand write the shit so it doesn't seem like you are a "real" company but someone sending personal mail. It is a lot less suspicious. Remember the best place to hide something is right in front of their face. Our safety and yours is number one over greed. Patience is more valuable then a life time in prison.
Edit: Don't use handwriting then. Make many different labels with different addresses and companies. Sorry for the bad advice. Moral of the story change your shit weekly.
Never hand write anything. Extremely bad advice there.