Shipping within the United States will usually be through USPS or UPS through Pirate Ship. Tracking numbers will always be provided.
To keep International shipping costs to a minimum, shipping is done through Pirate Ship Simple Export. This is typically a combination of USPS, Asendia, and a local courier. I do not know which local courier in your country will be used and I cannot request or designate a courier.
Shipping to Vietnam must be done through FedEx or DHL (usually FedEx) due to issues with their postal system. International shipper MUST provide a valid phone number at checkout.
All local duties, customs, taxes, VATs, tariffs, and other fees are the responsibility of the customer. Customs clearance procedures are the customer's responsibility.