Wear them in the most straightforward way, but choose brooches that really echo your personality. They're easy to find at flea markets and vintage shops. Price really isn't important here, these are more of a statement. Attach them to the shoulder of a plain top or the lapel of a blazer or sweater to dress up a simple look, or accessorize a plain dress this way for a more unique look.
It's so easy to get creative with brooches though. String one onto a chain and turn it into a statement necklace to add options, but use the popular collar trend to your advantage and fake a statement necklace with a bigger brooch by pinning one to the neck of the collar right in the center of the two flaps. I did this with this Target dress that I totally copied (and got on sale!) from Blair Eadie there and the brooch pictured above. I was wearing it during the day, so I threw on a thick sweater jacket and tights and shorter leather boots to make it a little tougher and more casual. If your brooch is a little smaller, pin it to the corner of your collar for an eye catching detail.
Go a little early 2000s with your brooches and bunch them on a jean jacket collar or shoulder. Or you can add them to a bag if it wouldn't ruin the fabric, or pin one to an artfully slung scarf. If you're wearing a blouse with cuffs and aren't rolling them up, you can add one or a few to a cuff instead of a bracelet or watch.
Keep an open mind next time you're browsing for accessories and pick up a brooch. When making an outfit and none of your existing accessories seem quite right, it might be just what you need.