This is something you should save for last.. When everything is done.
Step 1: Flatten all your layers (but god whatever you don't don't slip and save as the same psd and close photoshop.. You just lost all your layers. :) )
Step 2: Make a copy of your background layer and make the copy the active layer
Step 3: In Photoshop go to Filters/Other/Highpass. Mess around with different values. Usually anywhere from 1.0 - 2.0 is all you'll need.. Experiment as you wish.
Mine looks like this:

Step 4: Set the blending mode of your new layer to "Overlay"..
You're done.. You should now notice (click the layer off and on) your texture now has that little extra crispness and sharpness to it to really make it stand out better.
Before:

After

In game
