For me this is a constantly changing, seasonal pack and repack.
Currently I am just going from my winter load: tools, tubes, yak trax, extra balaclava, 2 pair dry socks, extra fleece top, leather chopper mitts with heavy wool mittens, spare liner gloves, ski googles, chemical hand and toe warmers, scissors to open their packages, food, and cellphone. I just took out the extra fleece, leather mitts, yak trax, goggles and heaviest pair of socks. That made room for my camera. I'll add the artificial tears soon (they won't be frozen) I find them very helpful on long windy rides, but they are useless in the winter. By summer, all the gloves will be gone. The free space gets used up by maps, camera, sunscreen, bug repellent, etc. The weight is replaced by the extra water I carry.