I speak from experience, not theory 
Live view is a good way to judge DOF, but as I have mentioned earlier on. I often do take some extra shots at different apertures and then judge in Lightroom which one looks the best. Sometimes I prefer a shot where the main subject is in sharp focus and the background slightly blurred. I'm not suggesting DOF calculators as the main tool at all, I think DOF calculators are great for getting a good feel for DOF at different focal lengths and apertures and in a given situation it is useful, however I would always in a challenging situation use live view and aperture bracket my shots.
A lot of useful thought have been expressed, so forgive a little redundancy and read on. When I acquired my Canon 5Dii, I thought that live view was there to satisfy the point and shoot crowd, only to find how valuable it was for focusing landscape images. If you want to make large prints and have the scene believable, the foreground has to be in really sharp focus. As others have said, it is not crucial that focus be maintained to infinity. Some print viewers feel that sharp focus at infinity is unnatural. I feel that hyperfocal distance techniques are, for the most part, obsolete and less than adequate. Using live view, 5x or 10x viewing, and DOF preview, you can often get adequate depth of focus at f8 (full frame). However, the best results are obtained with focus stacking because you can control exactly what will be in focus and use an optimal aperture setting, like 5.6 or 8, to keep diffraction in check. Did I mention a tripod?
