There are lots of lovely cloud pictures on Flickr, not just in the Cloud Appreciation Society group. The ones that I find disappointing are those where the photographer has been heavy-handed with Photoshop (or other photo-editing software). Clouds that are big, bright and blousy become hard and set in an inky-blue sky, if you use the auto-editing buttons. This happens mainly when there's nothing else in the picture besides clouds and sky - no land or seascape. For example:
This is a picture of some fat cumulus clouds -
and this is what happens when you click "auto-levels" or "auto-color" -
You may have a good reason for doing this, if you're doing a photo-montage that's especially dramatic, perhaps, but otherwise I think that clouds look best when they're natural, which means gentle editing.