A label maker is a great thing -- label every blessed thing -- drawers, boxes, shelves.
I also like to take a photograph of the nicely organized area, print it out, and post it, say, inside the cabinet door, or on the drawer bottom. It helps me keep things where they belong, it's a quick visual reference of what I have in that box or drawer, and if I have the photos in a file on my handheld or phone, I can use it as a quick reference when shopping, and thus avoid re-buying things I have already.
If you are overwhelmed by the sheer volume of stuff -- one strategy that might work for you would be to box up and store something like 25 to 50 % of your stuff, and just get the remainder under control and in a system that works for you. Then, once you feel under control, you can "Shop" in your storage boxes, and slowly add those items into the working stash. They key there would be to avoid buying anything more before checking on what you already have in storage.
RST