Everything came from the craft store. Small fake mum, cardbord circle backing, 7/8" ribbon (three types), charm ribbon, and a hot glue gun. The trick is cutting the ribbon to make the triangular shape. For this thickness of ribbon, I cut an angle off (about 30 degrees). The long side measures about 3 1/2". Fold on the short side and then double over as shown in the second picture. The ribbon can be stapled together. Repeat several times with the different ribbon. Hot glue onto the cardboard circle in the pattern shown, and then glue on the mum. Lastly add the long ribbon and charms.
The girls wanted to wear them on their arms and so I made scruncy-like bands that were safety pinned to the back of the mum. Each mum was about $5.