I like dodging and burning many of my images. Flat low contrast scenes become more interesting, and the image takes on a three dimensional appearance. Landscapes, portraits and travel images often look better with a little dodging and burning. My preferred method for many years was selecting the adjustment brush in LR, adding about .5 exposure, and brushing over areas I wanted to lighten. Often times my approach was simply lighting areas that were already slightly brighter in the image. This technique works. Remember to reduce your brush flow to around 60 so you can seamlessly feather the effect.
But there is another way to dodge and burn, which often gives a more seamless effect and is easier to do. Try using the Luminance Range Mask. Take a look at the image above. The green ridge tops are slightly brighter than the valleys. The scene is uniformly lit, so there is not a lot of contrast. To help this image, I want to lighten the ridge tops. Here is the process. First, select your adjustment brush. Next, set your exposure anywhere from .5-1 in value. Now brush over the entire part of the scene that includes the areas you want to brighten…no selective brushing needed (set your brush flow 80-90).
Now, go to the range mask and set the method to luminance. Grab the left triangle slider and move it slowly towards the right. This will reduce the brightening to only the areas that were brighter in the first place, in this image the ridge tops. Very cool! By adjusting these sliders in the luminance box you can adjust the areas where your initial brightening was applied. Much quicker and more seamless than manually using the adjustment brush and selectively brushing highlights. Give it a try, you will soon be using this all the time!