What protocol should be followed during international flights regarding customs?

During international flights, it is essential for flight attendants to inform passengers about customs procedures and provide necessary forms. This ensures that passengers are well-prepared to comply with the regulations of the destination country. Proper communication regarding customs can help prevent delays and confusion upon arrival, as well as avoid potential legal issues for passengers who might not be aware of the specific requirements they need to fulfill. Providing these forms in advance also helps passengers fill them out while still on the plane, allowing for a smoother transition through customs upon landing.

In this context, the other options do not align with best practices in aviation safety and passenger service. Ignoring customs procedures can lead to significant complications for travelers, while allowing passengers to figure out customs on their own can create confusion and increase the likelihood of errors. Reducing preparation time to expedite boarding compromises the thoroughness required for compliance with international regulations, which can cause problems for both the crew and the passengers upon arrival.