Don't use Fragile stickers !
Having spent a reasonable amount of time working at a courier firm, it's quite amazing what you see when spending a few hours watching how parcels are sorted.
Parcels emblazoned with FRAGILE stickers, are always targets. The let's see how high we can throw this one game is, I'm sure, still a favourite.
When this particular company had the contract for delivering Dell kit, I was quite amazed how well a 19" CRT monitor box would roll, corner on corner, down the chutes of the sorting machine, rather than slide !
Parcelfarce, Sh*tty Link, Oops, etc. They get their names for good reason.