Digital BW, The Print

Or duplicate the sky portion of the image and set blending mode of that
layer to multiply, then dial down layer opacity to where it looks right.
Also a good way to build up detail in overexposed images.

Isn't that the great thing about Photoshop--there are always a million ways
to skin any particular cat....

Doug 

> 
> Here's a variant method that might work also: create a duplicate layer
> and invert it, then use curves or levels to darken to taste. Still need
> to work on the delete the bottom of the image on the duplicate layer and
> work in detail on the transition, but this might get you to a darker sky
> faster and with less potential for degradation.
> 
> Bernie
> 
>>> After 2-3 years of digital darkrooming and B&W printing I am still
>>> not happy with my methods to darken blue skies.
>> 
>> Take a snapshot, adjust curves to make the sky as dark as you require,
>> take another snapshot <snip>
>>