I try to geotag everything. If was carrying my GPS I use GPSPhotoLinker to sync the data into the raw photo, and so the tag will generally be fairly accurate unless the clock on my camera was off. Otherwise I have to try to work out where I was, which is generally fairly accurate if I do it reasonably soon after taking the photo, but if it's a month or two later I can easily forget, particularly when I'm in the middle of a long period of travel. In those cases I try to make my best guess, but if something appears to be in the wrong location (even very slightly), please let me know.