The problem with all these methods of concealment is that they are easily detected by an X-ray. Modern X-rays provide colored output for the operator where organic substances are easily identified. When they appear in places where they are not expected it is almost guaranteed that this is a shipment of narcotics of sorts
I don't run any operation as I'm just a casual shopper but I like to have my stuff hide in plain sight. So for example, if I hypothetically ordered 50 g of cocaine I would have it vacuum sealed in a bag, I'd have the vendor print a label with product information for caffeine and put it on the bag. The package would include a printed invoice, a business card, leaflet with other products and other stuff that is common for a package from an e-shop with vitamins and supplements. The shipper must use professional packaging and you may need to pay him extra to go get that nice cardboard box and stickers for the label but for me it's money well spent.
In case there is any abnormal delay at the border, or the package gets seized, I just consider it lost. It is shipped to a virtual identity that is unique for each shipment and does not link to me.
Obviously this cannot work for all types of substances but I reckon that it may be the best strategy for white powders that can be easily declared as a different substance that looks identical.