I love brooches in all forms, you can use fabric that you have on your home like of an old trouser or an old tshirt or something like that. I usually do this things for a present and while IÂ´m watching TV :)
I hope I gave you some ideas and you like what I did.
You draw on a paper what you want to do and cut it, tis will be your template.
You put your template on the fabric and draw the edges with a pencil, then cut the figures. You will always need 2 parts: front and back.
In the fabric that will be the back sew a safety pin or whatever you have for doing this as a brooch.
Begin to sew both parts together and leave a little hole, then fill it with cotton and finish sewing.