I've stayed off this thread so as not to derail it, it makes interesting reading to see all the responses together! I'm not sure I have favourite conditions, but some interesting ideas about overcast days so no dark shadows (which has worked well on some of my pics, thinking about it, but that wasn't be design), or a bit of mist to give some perspective and interest. Maybe on those days there will be more colour in a month or two, right now there's mostly just a range of browns - maybe that means it's monochrome season!