This shot is about 220 degree view - not quite to 360 yet but does pretty well for a render so far - and I haven't made it higher yet. I need to add some more sky above so I don't get any vertical stretching This is a pan stitched from a number of images (I think this one was 4-5) where I mostly just took the clouds from them and made my own sky as a gradient with the tweaking.

You can take panoramic shots (multiple images - then stitch them together so it's seemless) or just take a whole bunch of images of sky and clouds and put them together like this one attached where I pretty much made "brushes" out of a number of cloud images, and made my own blue sky for them to be in.

Start taking pics of clouds and skies in general and toy around in PS.
Does this help?
-Lew ;-)