well when you know what your doing you try to keep your ISO as low as possible.
I do try to keep ISO as low as possible. I shoot aperture priority on my 6D (unless I'm using a speedlite) and set the auto ISO to stay low until correct exposure needs a shutter speed about 1/2 stop faster than the focal length of whatever lens I'm using at the time (yet another good reason to use prime lenses :-). I just have to set the aperture to whatever is appropriate for the scene & the auto ISO & auto shutter speed does the rest.
This setup works marvelously, & I wish my older cameras had it as ISO really is a "3rd priority" in addition to aperture & shutter speed.