I've got a small, multiple pocket pouch on a tool belt and in it I have:
awl
2 digital thermometers (with magnets on them)
hand-sized l.e.d. flashlight - wonderfully bright
telescoping mirror (don't use too much)
a magnet with different screwdriver bits attached to it
CO detector clipped to the pouch
Also on the belt, in their own separate pouches, I have:
Suretest 61-165
IR thermometer
camera (couple of extra batteries in the bottom of the case)
Tape measure on the belt too. Hand towel around the neck (I perspire profusely - in case you wanted to know) plus it's great for keeping my hands dry when I'm testing/filling sinks and tubs.
I just bought a Suretest 61-059 (got it Thursday). I'm going to switch it out for the bigger 61-165 and see if I like it better for size and speed of operation.
When not in use, the tool belt rides in a tool bag that also has a 4" ball, house slippers (for being considerate), Ryobi small vacuum (sucking up attic insulation), and my latest cordless screwdriver
BOSCH PS20-2 10.8V Litheon Pocket Driver With 2 Batteries - Toolup.com}
It's GREAT and light and one battery lasts a very long time.
Crawl stuff, ladder, binoculars, extra towels, sniffers -- out in the truck.
I, too, have been trying to figure out how to get small/efficient. Working on different things. Having fun.
Wow, that's a long post. Hope this helps someone.
Bruce