I never bother looking at the histogram on my Nikon cameras. I choose my shutter speed and ISO by looking at the exposure meter in the viewfinder, using a single square focus and exposure point, and AF/On or AF/L button for focusing.
If the shutter speed is too slow for the conditions, I increase it and manually increase ISO, or take advantage of the ISO-invariant nature of the Nikon cameras. There's usually a slight advantage in increasing ISO. The cameras are not truly ISO-invariant.