Once again, the Retouch tool allows you to concentrate on just the portion of an image you want to affect.  So if I only wanted one section of my little design to be lighter or darker, I would use the Retouch tool, Lightness Up or Lightness Down.

Burn and Dodge are Photography terms.  To Burn is to add light, making the image darker.  To Dodge is to hold back light, making the image lighter.  You will get different results with Burn and Dodge than you do with Lightness Up and Lightness Down.  It keeps more of the color and the image intact while adding the effect.

Color To Target is another art form.  The trick here is to use a low Opacity.  It is better to click the color on a few times rather than trying to get it all done at once.  Be subtle.  Play with the Opacity and the Size of your brush.  Depending on what you are coloring over, you may have to pick another color to apply to get what you want.  You can do some great things with the Color To Target to fix old photographs.

I haven't really had any big use for the Hue To Target, but I have used the Saturation To Target on several occasions.  It's more of a trying it out thing.  You have to play with what color to pick for your Styles box to get a result.  In the image below, I got an interesting effect when I used Yellow Saturation To Target on the rather dull greenish planet.

The Retouch tools are fantastic for touching up and fixing graphics.  There may be some other tools under Retouch that you find very useful.  I've covered the ones I have found the most useful.  You know what they say about too much information!