I too use the tomato and section off for sizes and uses. I use each 'section' for the use, as in jeans, sharps, embroidery, etc. Then I have drawn 3 horizontal lines to divide the sections into 4 or 5 parts, for the sizes.
I use this guide to tell me what kind of needle it is when I can't see the shank to read it. This is for needles I have used, and I use a plastic case similar to the one above to store the small cases of needles.
http://www.euronotions.com/pdf/Schmetz_Sales_Guide.pdf