To make your maneroll, take about 8 ft (less for the minis) of stretchy material, fleece is mostly used. Cut a 4 inch strip if you want to stitch the edges and turn it or cut that down to 2 inches is you don't. I like to use contrasting colors so it would be 4 ft strips of 2 colors sitched together.
To make rosettes, head to your local crafts store. You can buy the individual flowers. Roses are most traditional. Red roses on a Haflinger would look sharp. Cut the leaves off and cut the stem down to about 6 inches. The crepe flowers are more involved and you need floral wire and tape, crepe paper, ribbon, gluegun... or you can buy them.