Feel free to C&C as always - anything I can do to improve is highly appreciated!
This could be the blind leading the blind as I don't know much as well. However, from "my" experience, I only crank up ISO during lowlight situations where my lens is not fast enough to capture an image without blur and/or I need a good DoF to capture everything so I need to go down to a smaller aperture. If I don't need to get fast because light is great then I use the smallest ISO possible at all times.
Like I said I can be wrong but that's what I do .. Especially during day shoots because I have to much light and a higher ISO is going to be to much light for into the sun pictures ... I'll probably go a little higher if I'm shooting something in the shadow and with a small ISO my shutter go under 1/60 then I might crank the ISO a little to get in the 1/125....
Once again I can be totally wrong but that's what I do ..