There are a few guides on eBay to help you in creating your shipping policy. More importantly, your buyers will be happy to know that you accept valid returns (just in case!).
Just I am wondering, if your question pertains to how you are to ship a product or how to go about creating your policy with your buyers? Or both?
The easiest way to ship internationally is through eBay's Global Shipping Program.
If you prefer to handle international shipments yourself, here are a few things to consider:
Research your shipping options in advance. Decide where you're willing to ship to, and select a reliable shipping service.
Specify in your preferences that you want to customize international shipping.
In the International shipping section of your listing, specify the shipping cost and service. If you select calculated shipping, the cost will be based on the buyer location and the size and weight of the item. You must specify shipping to Australia, Canada and the UK for your item to appear on certain international sites.
In the Description section of your listing, clearly indicate that responsibility for any customs or import duties is with the buyer.
When you ship the item, remember to select delivery confirmation. For items over $750 in value, we also recommend signature confirmation. These options can help protect sellers from eBay Money Back Guarantee cases.
If you don't want to ship to certain locations, you can set up shipping exclusions.
You can view more about the Global Shipping Program here - Link hidden: Login to view
Hope this helps.