I ship a lot of items that I sell on Ebay internationally. I've shipped all of them USPS. I've kind of learned by trial and error what the best way to ship internationally is and one thing that is really important is to include shipping insurance in your shipping cost. You want to do this because just like with regular U.S. mail, if the package is lost you can only make a claim if their is insurance. You can insure items that are shipped priority mail international(with the exception of the flat rate) and express mail international, and the express mail option(although more expensive) has better tracking information. If you start selling internationally, you will probably have a lot of buyers who want you do mark the item as a gift or declare it for less than what it's worth on the customs declaration so that they can avoid customs taxes. I would avoid doing this because if the item is lost, it's only insured for the amount you declared it was worth. The paperwork is pretty easy and you can do it right on PayPal, but have to add the insurance at the post office. Right now insurance can't be added though PayPal for international shipments and the USPS click-n-ship website is messed up and won't allow you to add it for the time being until they get it fixed. Overall I haven't had any problems so far. I think that a lot of sellers avoid shipping internationally because it is more time consuming. I have personally found that you can make a lot more money if you do ship internationally. If you have any other questions you can PM me or email me any time. You can also find a lot of info on the USPS website. Hope this helps!
Vicki