I put the word out in my office about my haberdashery obsession. Button's ribbon and odds and ends of fabric. I didn't do it to make anyone feel guilty, I was saying that I LOVE buttons, beads, ribbon and fabric and have a huge stash and love making things for people. Lots of babies due before I had mine in December and made lovely gifts for them all from my stash. But gained so many donations. One lady had been left this stuff by her mum and she has no interest at all in it and was going to bin it all. Three black bags of vintage fabric, ribbon, ric rac, lace etc. Two huge sweetie jars of buttons. She didn't want anything, but have given her 12 jars of honey as a thank you.
I have an old chest of drawers from my great great aunt which I keep my ribbon & fabric stand in. I have my buttons sorted in shades in various pretty jars, mostly courtesy of great great aunt again, the sweetie jars are full of whites/natural and browns/tans. I love my buttons, but I do try to use them in my craft projects, or it would be a bit weird just stashing them.
Charity shops have been most successful in enlarging my stash pre-work colleagues. Often they'd have a jar or tin full. I also like beads too, charity shops and jumble sales are great for these.
My mum is a hoarder of everything, I like to hoard haberdashery. MiL is fabric obsessed only and her mum button obsessed. I love love love my collection, and the envy of all my friends.
There are many people I know who just don't understand why you would want to keep buttons, ribbons, fabric.
I am itching to start a new project just limited time with DD as she's almost crawling and has a great snatch reflex of whatever I am working on.
eBay is a great way to expand as well, often bought the odd baggy of mixed buttons. Often searching by distance first can help you make a decision on whether to buy, you can cut out large postage costs if you are happy to collect. Often find the postage is high because of the weight.