About a good 5 months into my Mega Man fandom, I decided that I should start a few MM-related cosplays; 2 of which were versions of Tron Bonne from the Legends/DASH series. Now, most people make her brooch out of sculpey stuff or whatever, but in the world of being semi-poor and inexperienced in clay work, I can't do that, SO, using my sub-par sewing skills, a sharpie and some tissues, I made her brooch! (I made it twice; one for me, and one for my sister. She loved the pin I did when I showed it to her, so I made one of her for Christmas!)(In the pics, the first pic is my sister's pin, and the second pic is my pin.)
First, get your stuff together. At this point, you may want to make sure that if your sharpie is running low on ink, you either go find another one or find some paint. (My sharpie had ink in it, so I didn't need another one.)
Now, have your circular objects ready. You need one big one, about the size of a soda can bottom or a water bottle bottom. [/inaccurate size judgement fail] Make sure these objects are a *perfect* circle, regardless of how crooked-looking your pin will come out as. Use your big C.O. to make the front and back circles of your brooch. Cut those out as best as you can, and you have your front and back side!
At this point, I would find it wise to sew your pin back on whichever side will be your back. Keep in mind that you will need to have your pin back relatively level with the eyes on the front. Also keep in mind that the back of your pin will have the outside of the fabric outside the pin. (There's a reason for this and I'll explain it in a later step.)
Now, take your front circle, and get your sharpie smallest/second circular object, 'cuz your about to draw the Bonne symbol on the front. (You can find a clear large version of the Bonne symbol at Mega Man Legends Station, in the MML Wallpapers section. It's the first wallpaper on the first row~.) Draw on the symbol carefully, making sure not to mess up on the mouth or the eyes when tracing using your second C.O.
In this pic, you can see what the front should look like. (This is my sister's pin I'm working on, BTW.) The stuffing I used for her pin was actually Kleenex tissues, because I didn't have pillow stuffing. (I also didn't have it for my pin, so I used yarn for mine.) Have your stuffing ready because in the next step, you're gonna start putting together your pin.
Take your front and back pieces, and line up the pin back with the eyes. Grab your threaded needle and begin sewing your pin together. Don't sew it together completely because you still need to put in the stuffing, so sew your pin up halfway, then leave it be.
On stitching it up: The pin has to be hand-stitched because one) it's a bit of a hassle trying to sew up something so small on a machine, and two) it takes less thread to sew up. I think I did something like a weaving stitch, but I'm not sure.
Now take your stuffing and stick it in the pin. Don't get too much because then you pin will be too spherical and it will look odd. Making sure it's not sticking out, sew up the rest of the pin, tie your thread, and cut it.
And then, with a flourish of the hand, your magical wand, and a Keyblade if you have one on hand (if you're a Briefers Rock fan, DO NOT MAKE THAT REFERENCE), you now have YOUR OWN TRON BONNE PIN!!
If there's something wrong with your pin at this point, it might be safe to assume I wasn't clear on something. Feel free to ask me if there's any questions!