There is some fascinating information here about using them for inspiration. [Click on the box headed HTML version]. Prunella Clough is another artist I had never heard of - and I should have done!
The section 'Inspirations' is fascinating for those of us who think real artists don't use photographs in their sketchbooks. I'm sure Clough used sketches as well, but reading about her working methods is very helpful for those of us trying to develop our use of sketchbooks. Photos and words I can manage! I found the section on how she used cropping interesting. We were often told to do it on C&G - but I found it difficult to get away from wanting to use the whole of whatever image I was working from. Clough's work encourages me to try again.
I got the link from Mags Ramsay's blog - well worth looking at for her comments on art as well as an excellent post on using colour catchers in textile work. [Something else not to throw away ...]
Getting back to pictures - here is today's. More witch hazel, although very different from the shy retiring little flowers on the yellow one! Mmmm - perhaps i need to try cropping this one a bit ...