I rarely do a PFL in open country, but I will spring a 'pick a field' on my self every now and again, particularly when I know I'm being slack. If I'm feeling vunerable, I'll go the whole hog and constantly keep identifying and re-selecting new 'options'.
If I am in open country, I'll usually break off at about 500' for three reasons:
1) Don't want to annoy the neighbours, be they animal or farmer,
2) Don't want them to report me...
3) Still gives me height to make a Pan/Mayday call if the aeroplane lets me down at the last moment!
If I've screwed up, I might take it lower to check that I can get in somewhere else, but if it looks good, I'll break off.
However, I do carry out PFLs back at the airfield as often as possible, and then of course, it's all the way down to the bottom. During the summer months, that was every flight, as I would glide in towards sunset to keep the noise down!