I use the tiny little craft ziplock bags. I sort just as they are when they are put on a button card. Then I file the bags by color. I repurpose buttons so I get quite a few and do not want to do the pour and sort everytime I need buttons. In the bags I know just how many I have and if they will work for my project at a glance. I store the bags in the plastic bins with drawers that the guys usually store nuts & bolts in.