I had to make several, but not 100 (!), for the sides of a Minnie Mouse Cake. I just cut a strip the width I needed and laid it flat on my mat. Thinking of it in thirds, I picked up the left side and laid it over the middle to the right. Then I picked up the right side and laid it over to the left. It looked kind of like an upper cake "K". Then I just pinched the middle together. If the ribbons are big enough you could cut an extra little piece and make a band around the middle.
I hope this makes sense.
Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday. See. There is no "Someday"!
Do you have a diamond shaped cutter or impression mat? Or you could use a ruler to measure and cut out diamond shapes.
I would roll the fondant on the thick side, Make two marks in a 'v' shape with a veining tool or even the blunt end of a small knife in the pointed ends of the diamond. Then cut the diamond in half so you have 2 triangles. Turn the pieces around so the pointed ends you marked are in the middle next to each other.
Use a large round frosting tip to cut a circle and put in the center to make the center of your bow. You can fold the edges of the circle around the middle if you want.
Then I would use a small round frosting tip to cut out white "polka dots" to put on the bow since it's minne mouse themed.
I hope that makes sense, I did it this way for my nieces birthday but I don't have any pics 'cause my camera was broken.
If you have a pasta maker, roll and cut the gumpaste/fondant using the linguini maker to get lots of long ribbons. Cut them in 3" lengths (or thereabouts, depending on the size bow you want. Fold both ends in to meet in the center, do it over dowels to keep the loops open. The roll a small pea sized ball and flatten it some with your thumb to make a button-like center. I did lots of these for this cake and it was really easy.