I am not in the habit of plugging software but I have found this so useful since I bought it a couple of months ago that I felt I should. I use it on practically every image I process in Photoshop. What is it? It is an 'extension panel' for PS (CS5 and above) (I have only used it with CC). It is a panel that creates luminosity masks and also helps you use them. If you are familiar with luminosity masks you will know that while they can be incredibly useful, they are difficult to create and pretty time consuming to use. Often they can be more hassle than they are worth. This extension is incredibly well thought out and put together and really takes out all the donkey work in using luminosity masks. Most of the relevant information is on this page. http://gregbenzphotography.com/lumenzia/ It costs US$39.99. Unfortunately, as it is an PS 'extension' there is no 30 day trial.