In reply to minus273degrees:
It depends on what I'm doing, biggest selection of technical gear I'd carry is:
1 x knife
2 x tibloc
1 x revolver screwgate
2 x prussic loops.
1 x micro traxon + screwgate.
1 x mobile phone
1 x snacks.
on a recent accident in the Dolomites we used all of these items except the traxon (though it was going to be used to haul the leader over to us, MR arrived before it was necessary) after the leader fell after traversing up and round a corner.
It's always possible to make do with what you've got on your rack normally but don't forget that the rack may be somewhere inaccessible (i.e. attached to the leader, 20-30m away, round a corner) so good to have a few bits and bobs attached to your harness to solve your immediate problems if something does happen. We'd have struggled if we'd not had personal kit that stayed on our harnesses rather than being part of the rack.
for the majority of mountain days:
1 x knife.
2 x prussic loops.
2 x screw gates (one large).
1 x mobile phone
1 x snacks.
for alpine / glacier add a long ice screw.
I normally (esp in winter) climb with a cordalette which doubles as ab tat and slings are always expendable.
Spent years humming and hawing about whether there was any point the carrying the emergency bits and bobs. One big lesson we took from it was that the 2nd needs to have the some kit on their harness as well - no good it all being with the leader if the leader has the accident.
They certainly made life a lot easier when the situation arose, though I guess you could use less specialist versions (i.e. prussics rather than tiblocs, regular screwgate rather than revolver). Also decided that it was worth one of my screwgates being a big boa as so much easier tying everything back to it when securing ropes rather than tiny lightweight things.
Cheers!
Stu