The basis for this idea originally came from a book I read by Kathy Peel called The Family Managers Everyday Survival Guide she suggested numbering Tupperware so that it is easy to get the container and lids together. I used this idea and took it up a notch. Before numbering the Tupperware get it all out and place the lids on top of the containers they belong to. Then organize them into similar groups, for instance smallest to largest or similar shapes. If you do the smallest to largest line them up accordingly and write the numbers on the lid and container. If your doing shapes group shapes together, then line up that group of shapes from biggest to smallest, and then write the numbers.
The next step really shows how nuts I am. I wrote a description of each Tupperware next to the number, for example: square, red, 3cups. Then if I am ever missing a number I know which one it is.
Finally, I grouped all the shapes together and enjoyed a very organized Tupperware cupboard.