Security, packing and protecting the contents from the elements need to be considered. Padlock all your zips together and take a chain and lock system such as the Cable Lock to secure your pack to a fixed point on long journeys, bus roof, railway station etc. where you may be distracted or lose sight of it. Pack your bag in a rucksack bag for transporting through airports - it reduces damage and can be used as a separate holdall if you need more space or want to split your luggage. Use packing cubes and dry bags to organise your clothes and bits and pieces - they will also protect your contents from damp, sand and rain.