different scenarios require different gear (imho)depending on what I am doing, On days when I may be out all day & things may change trout fishing I use a vest. loaded with all manner of flies, spare sinking tip spool, net, etc...Fishpond brand is my current vest.
I also have a Fishpond chest pac and combo back pack rig I take with me when hiking along way from the truck. Brookie fishing in small streams mostly. I can carry lunch, camera, extra shirt, water etc in the back. Up front I have a fly box & some tippet spools etc..
On days when I am not far from the truck, Road fishing I call it, I just use a shirt or the pocket in my waders & carry a few flies and a some tippet spools, hemostats and floatant. What more do you need? The vest stays in the truck if I need something from it.
Most of my salfwater fishing is done from a friends boat so I have a big bag of gear that I take along.