At the time of customs clearance of your personal effect shipment in Australia, you may be asked to fill in Packing Declaration form.
This form is for the Australian side only and you can download the form at the following page of the Australian Customs.
The form needs to be completed by the person/company who packed. In the case of a personal effect shipment, the form should be filled out by the owner of the goods who is the shipper and knows about the packing materials used.
As you see, the form itself says “MUST be issued by the packer or supplier of the goods.” i.e. by the party who packed as this declaration form is about outer packaging.
The vessel name and voyage No. should be the name of arriving vessel and voyage number. Normally you can obtain the info from the destination agent or the information may be already indicated in the arrival notice.
Answers to Q 1 and Q2 should be “No” as long as you used cardboard boxes only for outer packaging.
Q3 should not apply to most cases if the answers to Q1 and Q2 are No and no wooden materials are used for packing.
Then you put your signature, print your name and write the date. You may wish to check with your customs broker in Australia (or Australian customs) whether it is better to put the current date or a date before the departure of the ship from the origin.
With regards to the letter head, if you are an individual importing personal effects, simply putting your name address and phone number and making it look like a letter head should be okay.
At a glance this form may seem complicated, however, the important point is that the Australian Customs are simply asking you if you have used any wooden packing materials, which could cause a quarantine problem. As long as you are not using such wooden materials, it should not be problematic.