Pennanullar brooches have a nice look and are a great design. Just be careful to look at it from time to time to see that it does not turn on its own and get loose.

What you use it for depends on the size and weight. I have two of them that are in the 4-5 cm range - one of silver with a griffon head on each end, and one of bronze with a ball at each end. I use these on a couple of tams. I have a larger one about 5-6 cm diameter bronze with an owl head on each end that I use to hold scarves closed near my neck. I have two other silver ones a bit larger that I will wear with a plaid if I ever have one.