I visited a hiking shop yesterday and one man was there with his rucksack (he was looking at sleeping bags) and as I stood nearby I was struck by how much stuff he had clipped or strapped to the outside of his rucksack. His rucksack was on the floor propped up against a pillar and I noticed a phone and a GPS pouch and a little gauze bag as well, no idea what that might have been for? There was also a small bag clipped to the waist strap.
It got me thinking anyway. My tent is strapped horizontally on the top of my rucksack, my hiking sticks are secured to one side and I have one drinking water tube and nozzle showing over my left shoulder, but apart from that nothing else is attached other than a whistle and a small plastic cup. I do carry secondary items that are not permanently on my back, only clothes (usually socks and a baselayer) that need to dry before I can put them back inside my rucksack.
Over the years I've noted that some people carry everything inside their rucksack, they are so neat and tidy, whilst others like me seem to carry a minimum amount and then there are those hikers that appear to be cover the whole rucksack surface with something or other.