Inspired by the fellow farmer's market vendor who made these flower hairpins (she also made some with antique button on them), I embarked on a simple and fun project last week.
Then I gave them a good bath in warm water and mild soap. For some reason my great-grandma stored a tiny sample tin of moisturizing (greasy) hand salve with her buttons. It was in a cute little tin , but over time some of the contents leaked out and combined with dust to make an icky coating on the buttons.
Then I attached the buttons to bobby pins with a few stitches and secured them with super glue. And voila! I have an assortment pretty bobby pins for pinning back my bangs during the 25-50% of the time I don't like them. I love the vintage button pins. I thought about giving some of them away, but I'm not sure if I actually will...
Update: Please note that using the dab of super glue that I recommend will make your button and bobby pin inseparable friends for life. One commenter suggests using hot glue instead, which would probably yield more temporary results. I have an unreasonable aversion to hot glue, so I'd rather use super glue, but you might not, so there you have it. : )