When I started hunting with a flinter in the '70s I did so to experience what our forefathers experienced so I try to only keep what my be considered traditional in my shooting bag...
For each of my bags, I have a fixed powder measure and ball block on a leather thong, a short starter, a cleaning jag, extra flints, extra balls, extra lubed patches, a couple of extra pieces of leather to hold flints, some cleaning patches, a turn screw with knapping hammer attached, a small priming horn and a wingbone call...