RGB Gray - Burn & Dodge Layer
Create a new layer and name it "Burn & Dodge".
Make sure you are on the top most layer in the Layers Palette. This should be the Curves Adjustment Layer according to the workflow presented in these tutorials. Next, click on the New Adjustment Layer Icon at the bottom of the Layers Palette (looks like a ying / yang symbol). Name the new layer "Burn & Dodge".
Fill the new layer with 50% gray.
From the Menu Bar, click on Edit. Next, click on Fill. Make sure the fill box looks like the one shown here. Use 50% Gray, Blend Mode of Normal, and an Opacity of 100%. Then click OK.
Change the blend mode to Overlay.
In the Layers Palette, change the blend mode to Overlay.
Check your Brush Tool settings.
In the Tools Palette, select the Brush Tool. Look at the tool bar (under the menu bar). Make sure your brush has a hardness of 0%. Make sure the blend mode is Normal. Your Opacity should be 20% or less. Also, realize you can make the Brush size smaller or larger using the bracket keys.
Burn with black, and dodge with white.
Make sure your Foreground Color Box in the Tools Palette has the correct color for the correct application. When you want to Burn the image (darken the area) use black as your color. For instance, in this image I want to burn the tree branch to show more detail. When you want to Dodge the image (lighten the area) use white as your color. For instance, in this image, I want to bring out more shadow detail in the water.
*End tutorial*