Check the allowance on your booking
A bag's litre capacity does not establish that an airline will accept it. Measure its packed dimensions, including handles and wheels, and weigh the whole bag. Distinguish the included under-seat item from an overhead cabin bag and checked baggage. The former claim that specific 40–45-litre backpacks fit the strictest free allowances was incorrect.
For example, Ryanair's published policy distinguishes a 40 × 30 × 20 cm personal item from the 55 × 40 × 20 cm, 10 kg cabin bag included with the relevant option. Check the terms of your actual booking and every operating airline.
Pack for activities and laundry
Choose clothes that combine easily, then decide how often you can wash and dry them. A small starting list might include several tops, underwear and socks, two bottoms, a suitable warm layer and rain protection. Adjust it for your climate, activities and personal needs. Neither a twelve-item wardrobe nor four pairs of shoes is a rule.
Wear comfortable footwear that you have already used. Add specialist shoes only when the activities require them. Check the forecast and operator equipment list for hiking or cold-weather travel; temperature alone does not determine adequate insulation.
Liquids and restricted items
Security rules depend on the departure airport, transit points and jurisdiction. The US TSA liquids rule normally limits containers to 100 ml / 3.4 oz in one quart-sized bag, with exceptions such as medically necessary liquids and infant supplies. Do not describe this as a universal airline rule. Check the rules again for your return journey.
Keep batteries compliant and accessible
Read the watt-hour rating on a power bank. Spare lithium batteries and power banks belong in cabin baggage, with protection against short circuits. Check quantity, size and use restrictions with the airline; larger batteries may require approval or be prohibited. See the FAA battery guidance. Remove them if your cabin bag is checked at the gate.
A plug adapter changes the connector, not necessarily the voltage. Check your device's input rating and destination socket type. Carry the charging cables you use and a small backup where useful. Weigh the actual kit rather than relying on a claimed “under 1 kg” total that includes a heavier laptop.
Pack a small arrival kit
Keep documents, essential medicines, payment methods, charging equipment and a change of clothing accessible. Save booking and emergency details offline. Use water containers suitable for their intended purpose; a drinking bottle is not automatically safe to fill with boiling water.
This is an editorial checklist, not a first-hand record of 200,000 kilometres of travel. Continue with travel documents, budget planning and itinerary planning.