With my drawing yesterday I began by sketching out the outlines for my group of flowers and today the plan was to shade them in. The difficulty, as I'd imagined, was being able to see the tonal range available. So to make life easier I decided to manipulate my original photo by converting it to black & white and adjusting the luminosity of the image; this brought out the darker areas of the scene and gave me a template to work from:
With this useful aid I began by sketching in the very darkest areas with my 6B pencil and then moved up through the pencils to, I think, the HB level - this covered the right-hand flower in the middle. Then, as a contrast, I used everything from H to 6H on the left-hand flower just to make it look both softer and lighter. With the upper flower I ended up making it much darker than it needed to be and employed my rubber to remove most of the lead; the result is certainly very different in that it looks much less defined:
On the whole I'm not sure which approach I prefer. Where I've outlined the petals and shaded in the details I like the sense of separation and individuality for each petal but, equally, the top flower feels somehow more realistic in its softness and fragility. So each technique has something to recommend it but I think that having both in the same picture isn't necessarily the best way to go.