I am fairly new to scenery and am modeling eastern Utah, western Colorado canyons so not much trees, mostly scrub brush and sage and a few small tree's.
I haven't read this thread but following what Rob Spangler has been doing - I've started by getting course paint stripper pads from Lowes or Walmart and cutting them into small pieces and shaping and teasing them into small scrub bushes. Then I've been hitting them with a little 3M Super 77 adhesive and covering them with Eucalyptus or Sage ground foam. I've only done a small amount so far but with practice I am starting to get the hang of it.
As an aside, I've noticed now and then members reporting they lost all their pictures when their PC crashed. Gentle suggestion: you can buy USB thumb drives real cheap and copy your photo's over to them as a back up. If your PC crashes, you can always copy them back to the new one.