Let's share the ideas of our everyday clothes modification, which might help in carrying the survival stuff unobtrusively.
I have to obey a classic office dress code at my new work place now, so my favorite modification is the hooks in the pants pockets, which allows to carry many little things on key rings practically invisibly and comfortably.
All you need to do is to find a spot in the middle of the pocket's closed top near the waistband (between pocket's opening and the fly) and poke a hole in it from the inside of the pocket to the inner side of the waistband, so it goes through several layers of fabric for reliability. Then insert a piece of steel wire trough it and form a wide enough loop/hook on each end. Use some magnetic or clip-on key ring with a swivel to hang your stuff in the usually dead space of your pocket so it's not touching the bottom of it.
One of the more labor intensive but more reliable options is to poke 2 holes and thread-in a regular split-ring.