a perfect system

I love a system that works, and here's one that I've been enjoying lately.
My dear mother-in-law gave me this bag on wheels earlier this year, just as I was starting to read up on collage. To that point, I had avoided collage work because it requires so many little elements that I had no place to store.
But this little bag has compartments for EVERYTHING! AND it's absolutely portable. So as you can see, I have room for little bits of paper, a few paintbrushes, several bottles of liquid acrylics, various acrylic mediums, a few tubes of paint, a heat tool, etc. Everything I need to make a collage!
The wheels and extendo-handle turn out to be mighty helpful, too, because now that I've filled it up it weighs A TON!

How about you? Do you have a perfect system? If so, I'd love to hear about it!