1. Remove all old shipping labels and tapes. A little extra weight can bump you into a much higher bracket.
2. If the box corners appear soft add some tape to resist crushing and to help it slide.
3. All items should be double-boxed, especially heavy power supplies and sensitive items.
4. Tube rigs should be protected internally with newspaper or bubblewrap (never "popcorn"),
to limit direct vibration damage and the shaking of tubes loose - to then shatter.
5. There should be 2" of semi-rigid materials around the entire external perimeter of the inside box.
6. ALWAYS pack expecting shipper abuse -- then let them surprise you when they do not --
rather than expecting careful handling and be shocked when they damage your gear..

Warnings

Several countries have no insurance or package tracking system - do not ship there.

Get your money - in the clear - before shipping - especially to another country.
Ship with insurance and signature required - so delivery service is responsible.

If you accept funds via Paypal you could get burned by a false claim of non-delivery
not as-described, damaged, etc., even though you did everything right.

Beware scammers using fake, stolen, or expired Ham calls.
Never agree to cash a money order - then to give the "buyer" the "extra" funds.
This is always a scam and the MO will bounce -
leaving you with no rig, all the cash you gave him/her, and likely a bank fee.