I keep most of my kit in my laptop bag. It has a bunch of internal pockets and zippered pouches. I rebuild at my desk during my lunchbreak quite a bit so I like to have all my stuff handy.
My laptop bag contains...
Non-vape stuff:
Laptop (duh) and charger
Sony tablet and charger
misc small odds and ends
checkbook
Vape stuff:
Two or three box mods
One or two mechs
A fistful of RDA/RTAs
spare parts baggie
150ml+ of juice
Kanthal (24, 26, 28, and ribbon)
Rayon
DMM
510 ohm meter
tools
Nitecore i2 charger
8-10 18650s
a few empty needle tip bottles
and probably some stuff I'm forgetting.
This is the bag I use:
ProStyle
For running around on the weekends, I typically use a Maxpedition bag:
Bags & Packs - MAXPEDITION