I've shipped a number of pieces to the same location, and it's nerve wracking..... not to mention EXPENSIVE. I've lost one knife to customs (confiscated). The lessons I've learned is to be honest on the customs form(s). Also, I make it a point to ask the clients exactly how they want the knives shipped..... and make it clear that the client accepts ALL risks when it comes to shipping, customs fees, tariffs, etc.
One method of shipping that can be a bit scary, but it seems to be more and more requested...... USPS Priority Mail International. The biggest issue with this method is that once the package leaves USPS custody, the only method of tracking is the customs form. I think clients request this method because the cost of shipping is so much less than UPS or FedX.