Build your pre-travel checklist from primary sources only, because blogs and forum posts age fast and airport rules change faster. The core references: the destination country's customs authority website for allowances on alcohol, tobacco, cash thresholds, and prohibited goods; its agriculture or biosecurity agency for food, plant, and animal product rules; its health ministry or medicines regulator for medication and import certificate requirements; and its civil aviation authority for drones and battery rules.
Two more layers round it out. The destination's embassy or consulate in your country answers edge cases in writing, and a saved email reply is worth carrying. Your own government's travel advisory pages summarize entry rules for citizens and flag recent changes.
When sources disagree, the destination's own official sites outrank everything else. Watch the domains: official customs information lives on government domains, while commercial sites imitating them sell services and sometimes publish stale rules. Check close to your departure date rather than months ahead, since allowances and prohibited lists get revised with little fanfare.