Recently I got across some dark cloud effect in this gallery and one from a snapshot from the flim "Sleepy Hollows". Now I was wondering if I can produce the same in one of my projects.Can this be done with some plugin or with some post effects ?? I have a thought regarding Aurora Plugin and cloud brushes ........... but I think there may be better ways !!!! Can someone help me. I am attaching two pics to relate to my vision. Please help !!! This one is from the film "Sleepy Hollows"...........

This pic is from some artist at Cgnetworks.com ( u can see his name at the bottom). As I can remember he mentioned that this has been made with 3dMax,After effects & Vray.But cant this effect be reproduced in  ....... ok with at least some post effects with PS ??

the first one, you could likely do by creating two additional layers.. one you paint completely with a charcoal shade, the other set to a dark blue... you'd set the blue layer to an opacity that suits you... usually, quite transparent,  the charcoal , you'd "Send to back".. the clouds, you'd carefully use the eraser in brush mode, set to fully soft, and opacity set so that you create a faint transparency that lets the lower layers show thru, darkening the clouds. It takes some experimentation, but the results can be very striking. If you're working with a black and white picture, you can leave out the blue layer. The second one could be created a number of ways... most of which depend on what you have to start with when you go into post. Lou.