The New Forest down here is pretty good for generating mist, I think the soil mixture is such that moisture tends to hang around, and then combined with the relatively open areas, quite often you get low lying mist in the morning/evening.
As to deer, you just need to know where to look. Down my neck of the woods, there's an RSPB reserve at Arne where if you walk to the end of the reserve/peninsula, you're guaranteed to see a herd of deer pretty much all day all year round. The deer there as well seem much more people tolerant so it's easier to get photographs, plus with it being an RSPB reserve, there are bird hides scattered around the place, and the deer often walk by. Usually though the hides are only a good option first thing in the morning before you get the bulk of people in, as I think the deer are pretty good at hearing the noises from the hides.
Bucks by
Chris_Moody, on Flickr
Deer in rushes by
Chris_Moody, on Flickr
Those were both from Arne, in the morning. I say "first thing" but I don't mean crack of dawn (though I guess it might help). We're talking 9-11am usually.