Much like a makeup artist has her bags of brushes and cremes (and magic) and a doctor has her bag of stethoscopes and, well, whatever else she has in there, I have my bail-out bag--the things that I have to have whether styling for a photo shoot or getting myself ready on the go.
Here is my list of must-haves:
Match Sticks double stick tape (definitely the best brand out there)
Shoe polish (also good for scratches in your table!)
Safety pins (self explanatory)
Thread and needle (you probably have 50 hotel sets of these in your linen closet)
Scholl Party Feet - Invisible Gel Heel Cushions (again, the best I've found: they're washable and clear so discreet even in the strappiest of shoes)
The Original Gal Pal Garment Deodorant Remover (just buy a bunch and have them on hand--available at the Container Store)
Baby wipes (key for stain removal and odor removal, too).
Masking tape (for taping the bottom of model's shoes for the runway--you don't think they would just let them wear $600 shoes without taking precautions, do you?).
Just take them all, throw it in a makeup bag, and keep it in your car, your desk drawer, wherever you go, and you'll always be perfectly put together (or be able to fake it in a pinch!).