I posted this on my lj a couple of days ago, marvelling at how little I had to take on a particular job. The big suitcase is full of hair stuff (hot rollers, hot tongs, straightener, hairdryer, sprays, etc), the black and red case is my small travelling make-up bag and the other thing is my handbag, which is normally stuffed to the gils with random stuff I think I need to take with me. For big jobs I take two suitcases and a handbag that's almost ripping at the seams.
There's a full shoot worth of make-up in my squashy bag - look book (facecharts, etc), one blush pallette, four eyeshadow pallettes, four clamshells of Studio Tech, a palette of Kryolan creme foundation, two bottles of F&B, six clamshells of various powders & MSFs, a 15x10x15cm bag of misc items (mascara, gel eyeliners, small luminisers, creme highlighters, unpotted eyeshadows, etc etc etc), a pencil tin filled with eyeliners and lipliners, a MAC bag filled with lipsticks and glosses, brush belt, handtowel, plus bottles of make-up remover, luminisers, moisturisers various, bags of Dettol wipes, etc etc etc. The pocket at the front carries pens, an invoice book, business cards, and small crushables like false eyelash cases and consumables various. I still haven't unpacked it from Monday, I can take a decent photo of it later this afternoon.
I can seriously jam a lot into that case.
Edit: my bag is the one I was given as part of my old college kit. It's a bit daggy, but it's a good size for smaller jobs and it's taken a pretty heavy beating over time. You can get them at most make-up supply stores, but like I said, check out cooler/Esky bags at the hardware store - they work exactly the same and are much cheaper. Coming into summer, they're a godsend in hot weather - I stick a freezer brick wrapped in a tea-towel in the bottom of the bag and it keeps everything cool and unmelted all day long.