That's easy John,
As a seller, I always made sure I had allowed in the (extra) shipping charges, that it was insured and was a trackable and signed for on receipt delivery. I also only shipped within UK, I know that lost me some foreign bids and undoubtedly some money, but I didn't have the potential stress of trying to trace something that didn't arrive in language I didn't speak.
I sometimes under-estimated either the value it sold for, or the weight, and lost out when postage was due, but not often.
In more than 20 items, I was lucky no-one 'tried it on' and attempted to claim it arrived damaged - but my stuff was very well packaged and I took safety photos of the addressed parcel before posting. Like everything in life, plan for the worst
Cheers,