Yeah I do sell the odd item internationally, both on eBay and other sites. 

In terms of my items they are small and lightweight - so they can easily be sent as a letter. 

Some general tips:

-Research your postage options as they vary greatly from letter (approx $2.75) through to parcels (starting at $14.10 approx). Be aware of tracking costs as these can be quite expensive (just in case people ask about them)

- Collect a small pile of customs declarations from the PO and always complete them to ensure there are no hold-ups in delivery or returns to your door. It's a pain but you do have to do to the post office every time to lodge your items. 

Um I can't really think of anything else right now.