When I see a good sale on buttons, or some that are unique, I like to buy buttons in sets. Usually 6-8 for shirts and 4 for jackets plus smaller ones for the sleeves if I can find matching. (I'll probably have to increase the number on shirt buttons if I start making more long sleeve shirts with cuffs.)
I've been keeping my buttons in a basket, but after the recent 50% off of buttons sale at JoAnns, I knew that plowing through my basket was not the best way to keep track of what I have. I remembered an old hanging jewelry organizer that I still had in my closet and decided it would be perfect for keeping track of my buttons. I store jacket buttons on one side and shirt buttons on the other. Buttons are separated by matching groups and/ or colors and put in the individual pockets (see picture) Now I can quickly see what I have when planning out a garment without having to "dig"
Note: I only use this for carded or specialty buttons. I do have other bulk buttons in baggies in a drawer.