This is a simple tutorial on adjusting the dark and light parts of an image for greater contrast without using Brightness and Contrast It works on most images and can be done in any version of Photoshop.
Step 1 : I have opened this free stock image in Photoshop. It belongs to *Eirian-stock Iribel & Jillianiina
Step 2 : Press CTRL+J. This will duplicate the Background layer to Layer1.
Layer 1 is currently selected because it is highlighted.
Step 3 : Go to Filter>Blur>Gaussian Blur.
Step 4 : The Gaussian dialogue box opens. Place your cursor in the Preview window.
A small white hand appears. You can use it to move the image. Move the image till
you can see features like the eyes and lips.
Step 5 : Now drag the Radius slider pretty high till the image is blurred in the Preview window, but not
so much as to lose details such as the eyes and lips. You should be able to make them
out even though they are blurred. Click OK.
Step 6 : Now change the Blend Mode to Soft Light.
And here is the completed image. I don't suppose that will take you long to do.
Other photoshop tutorials are here