Preferred shipping in the US is PRIORITY MAIL. Insurance is optional: please let me know if you would like insurance and I will accommodate.
Outside the US is first class (for shipments less than 4 lbs) and Priority Mail (for shipments more than 4 lbs). If you want Priority Mail on a shipment under 4 lbs, please let me know. Note that insurance is available only for Priority Mail. And as I have found out the hard way, there is no traceability on first class mail shipments, so if the item doesn't arrive, there is no way anyone can see what happened to it.
If in doubt, visit the
USPS page and it has rates for US and foreign for reference.