I have been put the ringer shipping international and not knowing what works the best.  I avoid UPS like the plague when shipping international as my customers have complained and I have taken to the cleaners for the charges that came after I had already paid for shipment. What I have found is that USPS Airmail gets it done  easiest and overall less expensive.  This is mainly for US Ebayers.  My customers have been much more happier with USPS Airmail too. The main thing when shipping international is to get the buyers Phone number, and that is a big requirement when Airmailing through USPS. If you go UPS online Ground to Canada, expect to be getting signatures at your state capitalwhere the main office of Chamber of Commerce is located and also drive to your Nearest  International Airport to get a homeland security officers signature on your packages documents.They even required I put my Social Security Number  on the document and I had to get my customer in Canada to send me his Tax ID.   It cost me $2 to get goverment harmonized Code numbers to finish filling out the document online.  That was UPS online, I will never do that again.

Shipping to Canada and other countries has been real easy when I used USPS Airmail.  All I needed was my customers Phone Number and Address.  I filled out he paperwork in the post office and sent the item within 5 minutes.  I sent one item to Sweden and used USPS Airmail and did the postage through paypal and that was just about as easy.  Hope this help in International Shipping....