I love to color-code my files. So, in my filing cabinet, I have my home/church/business files organized by color-coded files, then use subfolders for detailed files.
I also like to keep my current business readily available on my desk. You could, for example, use a blue folder for "work", yellow for "family", and red for "Avon". When I was working in an office, I liked to color-organize by day (Monday was red, Tuesday was orange, etc.), that way I had my days planned out on what I needed to work on those days.
Set aside a few minutes each week to file away your things. You could also ask one of your older children to help with this (for pay or just to learn how to do it). This is good for them to learn for college, too! :)
If you want some personalized help, I would be glad to offer some other pointers. I LOVE organizing, and I know that everyone is different, and our lifestyles are different; so, what works for me may not work for you. But there IS a system out there that will. lol Don't give up! :) Kudos for tackling this!