Do not make any other strokes into the petals area, just the outlines. Shapes of the leaves are very easy. If you are observing them for a while and you’ll get the idea.
Shade the petals by gentle strokes from the bottom up. HB pencil will work well.
When you have all petals shaded, you can start to darken the leaves. Since this is a pencil drawing, it is good to make the leaves darker than the petals in order to get good contrast.
It would be different if you drew a colored rose, especially if the rose is dark red. There would be a little bit difficult to distinguish the dark tone shades.
You can soften the pencil strokes on each part of the rose using a cotton swab or tissue paper rolled on a toothpick. Both will work well. Personally, I like the previous drawing where the pencil strokes are more significant.
Do You Love Drawing Roses?