Spiderweb roses are one of the easiest to do. If you adjust the pull of your ribbon while you wind the ribbon between the spokes, you'll get the style you want. Mine is tight in the beginning and loose towards the end.
The 1 inch ribbon is 41 inches long. The spiderweb template is 3 cm in diameter. If you do it smaller, you will need narrower ribbons. I've done these roses on blouses and hairbands for me and my girls.
Also, through past experiences, if ever you embroider it on cushions, you will have to sew through the spokes and ribbons to 'hold' the 'petals' to the fabric so that little fingers and curious fingers will not pull the 'petals' out of place.
Last, I hope these pictures are helpful. Practice makes perfect :-)