For self-packing customers, it's essential to provide a clear list of items that require special attention or are restricted, such as lithium batteries. Here are some items to include in the warning for customers packing their own boxes:
 

1. Lithium Batteries

• Devices containing lithium-ion or lithium-metal batteries, such as laptops, smartphones, power tools, and electric scooters, need to be declared. Many countries have strict regulations for transporting these items due to the risk of fire.

2. Hazardous Materials

• Items classified as hazardous, including but not limited to:
  • Paints, varnishes, and stains
  • Cleaning chemicals and bleach
  • Aerosols (e.g., spray paint, deodorants)
  • Pesticides and herbicides
  • Pool chemicals
  • Fire extinguishers Customers should be informed that these items are often prohibited in shipments or need to be packed and declared properly.

3. Flammable Items

• Examples include matches, lighters, propane tanks, and gasoline-powered tools. Flammable liquids like kerosene, lighter fluid, and alcohol-based products should also be mentioned.

4. Pressurized Containers

• Items like aerosol cans, CO2 cartridges, and spray cans can be dangerous when transported due to pressure buildup during transit.

5. Perishable Items

• Food items, particularly perishables, should not be packed. In some countries, even non-perishable foodstuffs may require special documentation for customs.

6. Sharp Objects

• Any sharp items such as knives, scissors, or tools should be securely packed and labeled to prevent injury during handling.

7. Valuables

• Customers should avoid packing valuables like cash, jewelry, or important documents. They should be transported personally or using secure courier services.

8. Firearms, Ammunition, and Weapons

• Firearms and ammunition are often restricted and should be declared. Any type of weapon, including pepper spray and knives, may also be subject to regulation depending on the destination country.

9. Liquids

• Customers should avoid packing liquids that could leak and cause damage to other items. Any liquids packed should be sealed in waterproof containers and declared. Keep in mind if anything leaks inside the container it can cause mold to your items during the journey. 

10. Items Requiring Permits

• Plants, seeds, and certain animal products may require permits for international transport. It's important that customers declare these items in advance.

11. Restricted or Prohibited Items by Destination

• Each country may have specific regulations, check your countries regulations to make sure you are not shipping any items that may be restricted or prohibited. Country Guide for customs regulations