I love brooches, and I especially love making my own. Here is the simplest DIY I know, which easily makes an outfit more personal.
I used a doll-house painting, which I might get more of just for the frame so I can make my own paintings into brooches too. I also used a brooch back, the bit with the needle. They come in packs, so you can make lots of cool brooches. I have used safety pins in the past, and they work fine too. Now, just use a glue gun to attach the two to each other, making sure to cover the top of the metal with the glue so it can’t loosen. Then voila, a cool brooch.
For my mirror necklace I used a doll-house mirror, and just glue-gunned one of those hook screws too it. I use those mainly for making necklaces of of plastic things, since it can easily be screwed into soft materials. I have an awesome cactus necklace that I made using this technique. It always get’s compliments, even though it’s a bit weird to have a fake cactus hanging from your neck. But I like weird.