When booking fast shipping, focus on Weight and Volume Ratios (Dimensional Weight); most express carriers use a divisor of 5000 or 6000 to calculate billable weight. Ensure the provider supports DDP (Delivered Duty Paid) or DAP (Delivered at Place) terms depending on your tax strategy. For sensitive goods, verify if the provider has specialized handling capabilities for electronics (battery-compliant), liquids, or oversized items, and confirm they provide automated manifest filing to speed up customs clearance.