Generally don't like having things on the outside of my rucksack. Obviously things like skis, ice axes won't fit inside so have to go on the outside. Wet tents are another thing I don't want on top of my dry sleeping bag, so that is often on the outside. Likewise wet shoes if I'm crossings rivers or the like. Sometimes a camera clipping to my shoulder strap. Hat, gloves, tracker and a few other bits in the mesh pockets, but don't really class that as outside. I keep my compass in my thigh pocket to keep in away from my phone which will normally be in my rucksack lid pocket.