I also have been working on better clouds. Here is a couple renders.
http://farm5.static.flickr.com/4040/4442578716_30dbc6c729_o.jpg
http://farm5.static.flickr.com/4040/4442578716_30dbc6c729_o.jpg
Those are both the same picture. The clouds are getting there. They cover too much of the picture.
Oops!
http://farm3.static.flickr.com/2678/4442579856_0c5e2b5d54_o.jpg
hey man I've got a fantastic photo for u to practise
Like the clouds in the second one - but I'd shrink the trees a little.