Granma had a button box usually metal she stored hers. I have the box still and love to rummage in. Sets of new buttons I store in box in a plastic bag with an elastic band on, this means I can still see them.
Don't use buttons on quilts only knitting crochet items.

I use canning jars and sort by color. Sm jars for less buttons, etc.

Button, Button, Who's got the button?
 

What a fun thread!

LOL -- the OP's son was 4, is now 7!!

quiltingnoni, I just love your container!

sewbeadit, I thought I'd be drawn to the bright, fresh colors, but the tall container on lower left with the dull/autumn colors is gorgeous. What an eye you have! Those make a much more dynamic display than if you'd separated the different colors.

My buttons are all mixed together in a big glass jar I found at Walmart.

When I was growing up, my grandmother had a drawer of her sewing table reserved for the buttons that had accumulated over the years. I would spend hours sorting through the buttons, making matches and choosing my favorites...some were so amazingly ornate. It is a cherished memory and I believe that I will create such a haven for my grandchildren when they are a little older. All of us grandchildren were involved with dance, baton and other activities requiring ornate costumes that my mother and grandmother made...sequins and beads were something that required sorting and a creative storage solution. My grandfather made my grandmother a rack with baby food jars. He simply attached the lid to the undersides of the boards and then you simply unscrewed the color of sequins, beads, etc that you needed for a project. Depending upon the number of buttons, this would be a great way to store them, especially if sorted by color. My husband has said that he'll make be a similar rack for some of my craft items so I have asked my kids to save me baby food jars...I think I have a dozen, so far. I like the bigger ones.

I use an old tin that fruitcakes use to come in for storing loose buttons but if they are on a card, I stored them by type in a few shoeboxes.

Love this thread - especially the pics. I used to just throw all my buttons in a gallon plastic jar - like those that you buy pretzels or cheese puffs in from Smart & Final, Sam's, or Costco. When my MIL died over 10 yrs I inherited her sewing & knitting supplies & there were so many buttons in tins I began collecting the blue mason type jars as I ran across them in 2nd hand shops & actually sorted them by color for display. Everything came to a grinding halt w/major life changes for me including selling my home these past few years, but here is their current home.

What a lovely display!

I use Weck canning jars, purchased directly from their website (much cheaper than Amazon or Williams Sonoma) The jars are clear, have glass lids with rubber gaskets and clamp closed. I like them because they're easily stacked and their different odd shapes make for a nice display in my sewing room.

I store mine in the plastic bags that are designed for embroidery floss. The bags have holes punched in them and I hang them on the rings that you get at Staples or Office Depot. I then hang them rings on pegboard hooks.