I'm in the process of doing them now. I am using the five petal cutters, which work fantastic. I learned a trick with my wires that works really well. I make my cones for the center, let them dry, then I take the wire, heat the tip with a lighter until it is red hot, stick it in the rose cone. The sugar will melt around the wire, and when cooled it will stay adhered.
I keep a pad of Styrofoam and stick all the wires with the cones attached in that. My husband bought me one of the long nosed lighters that you use for starting grills, and it works really well.
Make sure you use lot's of corn starch on your table when cutting out the petals, and then keep the gumpaste under plastic wrap so it doesn't dry out. After my roses are dry. I hold them over a pot of boiling water, and it brings the color out, plus the cornstarch will melt away. Then I dust them with luster dust.
I did hundreds of roses for my fair cake this year. It should be in my photos.