I keep my supplies in labeled divided plastic boxes, by material and color. When I started, I thought I was doing great by putting my beads in unlabeled divided plastic boxes. Then the whole thing mushroomed and I was going crazy looking for a particular bead. That is when I decided to organize by type of item, material and color. Also, as soon as I order any item, I save a copy of the invoice in my computer. In the same sheet I prepare a table with the name of the supplier, description of the item and the cost per unit - including shipping charges. If the item was on sale or purchased wholesale, I made a note as well. I print the table and cut each strip containing the information and place it in the appropriate division in the plastic box. At least this way, when I am running short, or when I like the item very much and would like to have more of it, I know the name of the supplier, the item number and the price. This way I also have the price of the materials I may be using at my fingertips.
It is a lot of work, but I am finally getting used to doing it every time I order supplies. This system has also saved me from purchasing duplicate items.
I got tired just explaining the above. =)