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Luminosity Masks look like they might be interesting. Instead of picking and choosing parts of an image they isolate the lights and darks of an images. From there it's reasonably easy to work on specific pieces of an image. Although it masks the entire image, the Mask can be modified to pinpoint whatever you feel the need to adjust.
The "starting point" for a LM is the Channels Panel (that sort of eliminates using this technique in Adobe Photoshop Elements (PSE)).
First, make a new Blank Layer. To begin getting the information to make the Mask you simply Ctrl Click on the RGB thumbnail in the Channels Panel. This loads the Luminosity as a Selection. Go back to the Layers Panel of Adobe Photoshop (PS). Add a Layer Mask to the Blank Layer. You'll see that the Layer Mask looks pretty much like a B&W image of the original image. You'll have black, white and shades of gray.
To isolate individual tones, use either Levels or Curves Adjustments (Image/Adjustments) on the Mask. It doesn't appear to work using Adjustment Layers, so this is a destructive step. (Destructive to the Mask, not the Image.) Using this technique you can make as many tone controlled Layers as you wish. Since eight tone increments is about all the human eye can discern I'd limit it to a maximum of eight lights and eight darks Blank Layers with Masks. Depending on what you're trying to do it's probably more likely to use two or four Luminosity Blank Layers. (One or two for the light areas and one or two for the darks.)
To get the Mask for the dark areas of the image, copy the Blank Layer with the LM. With the Mask selected, Invert the Mask (CTRL I [eye]). With the Mask inverted you can now control what's going on in the darker areas of the image. Among other things, a shaft of "sunlight" was added to today's image by using the Brush Tool (B) and putting a yellow swipe on a diagonal coming in from the upper right. The soft light was put on a Blank Layer with a dark Mask. The Blend Mode was changed to Soft Light and the only thing that showed was a subtle glow of light.
LMs look like they might be a fun technique to explore. I'll post a couple more times with what I find.