I try to keep simple (but not as simple as Irvin)-in my tray (Ektelon H/Neos type tray), I have bent long nose pliers, side cutters, setting off awl and one starting clamp. Other tools and miscellaneous materials (string cutters, other awls, extra starting clamps, power pads, tubing) are in a very organized cabinet 2 steps away. I just limit the tray items to those tools I use virtually every time.
On my Baiardo I have starting clamp in the main tray, bent nose pliers in the left bottom tray, snips in the right bottom tray, setting off awl in the front hole of side tray, awl in middle hole, and string bed cutter in third hole.
My Gamma, I have all the same tools just thrown in together in the only tray.