Please don't just say DON'T sell overseas. Don't tell me there's only honest people in the US...
For example, for extra protection with Paypal wait for money to be deposited in your bank account before shipping. Bank transfer is also safe, you just have to wait for funds and you can trace back who sent it. A seller makes the rules.
Whatever the method WAIT for money to clear in your bank account before shipping, cashiers check included!
As for shipping, even with insurances, there's always a risk, overseas or not.