I love putting jewelry in my hair. I hook brooches in my hair. I also hook earrings and I unhook necklaces.
For my hair, I don't use bobby pins, I use Goody Simple Styles Pins to secure my hair. ''
I use the brooch to hook it in. If I use an earring or charm (from a necklace or wherever), I use a straight pin to secure it. If you are uneasy to get jammed with it (and you will so if you aren't willing to be uncomfortable the whole night), use a small bobby pin or a safety pin. The drawback is it will move slightly.
But it is pretty and to use a brooch is amazing in the hair.