I'm glad to be of assistance, don't mention it :)
I don't have any general "atmosphere scheme", but I do have a custom "basic sunshine" atmosphere that I use for startup. I have a few "User Settings" render modes saved, and my favourite of those are used for the majority of my final output renders. It may change as I learn and the posibilites improve.

My best advice would be to study the real world, and pictures (photos or paintings) with the look you want to achieve.
Then make a simple scene, and play with the atmospherics and light settings to get a grip of what the sliders do (one at a time!).