I most heartedly agree with bobt here. Spent somuch time trying to improve or corrrect my images in photoshop at first where i shoud have been trying to capture my image correctly in camera first and leaving as little wark as possible in ACR and lastly Photoshop itelf.
(1) try get you metering correct, App ,ISO, Shutter spped and know what to meter off for the day or location.
(2) Tripod or whatever to get the image as sharp as possible.
And offcourse not to forget your composition ,but i do think the above you should tackle first (Just my thoughts offcourse)..
Shoot in Raw and atleastyou can salvage as much as possible from your shot via ACR or whatever program you use and that will leave little to do in Photoshop itself.
Kept it short hoping not to confuse..
Hope this has helped..