Almost done, change the layer blend mode to Luminocity and the Opacity to 20-25%. This
will produce a “flattened” image. (Max is about 45%.)
Finally, put in a Levels adjustment layer on top and set the blackpoint, gamma, and whitepoint as desired. This effectively flattens the gross dynamic range of the image (which a normal High Pass does) while at the same time permits more of the brightness range in the histogram for image details.
If there have been big brightness changes, it may be necessary to adjust the saturation in the image (a Hue/Saturation adjustment layer can be good for that). As a rule of thumb, areas that get darker appear more saturated and areas that get brighter appear less saturated when there are brightness changes.