Creating  depth, better separation, and detail can be accomplished a number of ways.  Most retouchers use multiple curves and other dodge and burn techniques.  But by teaming your curves adjustments with channel mixing you can get a lot more from your images. 
Without a solid tonal structure to begin with, your creating a lot of extra work for yourself. [...]

In my lectures and one-on-one retouching sessions I like to say,  ” you’re only as good as what you change and how you change it.“  It’s important to think about what should not be retouched.  Usually botched commercial retouching is just plain sad but in this case… it’s hilarious!  Our friends over at Photoshop Disasters [...]