said by Edit This :

Open in PS > Image > mode > LAB. Image > Apply Image > Overlay > 35%. Sharpen in LAB and RGB using this technique: »Re: [FYI] Sharpening Tutorial.

said by samburgers :

It works better in LAB. For reason WAY too technical for me to understand.

I post therefore I am.

said by Edit This :

It works better in LAB. For reason WAY too technical for me to understand.

I post therefore I am.

said by Edit This :

An even better method is to go into lAB and then Curve. Adjust the "a" and "b" channels and lastly the "lightness" channel. Can be tricky but also can produce amazing results.