Ok I jump in !

Here is my way :
First, I almost never have an idea before beginning to play TG2.
So, I start with the terrain and try 1 or 2 simple fractal terrain. Then I try to find a nice pov with that simple terrain.
Now that I have this simple start, I create 2 surface layers (one for flat areas and one for vertical areas) and i connect 1 powerfractal on each ones with different colours and displacements to have a "taste" of what the scene might become... No need to be precise there, it is just a start.
Now, I have a starting scene with a colour flavour (if I may speak like that).
All I have to do now is to.... errr... improve the feeling of these colours with atmo.
And, as Volker said, I play with atmo (a lot) and then i go back to my colours to "adjust" them to my atmosphere values.
Then I add some details like stones (yeaaaah) or vegetation or water, etc...
I think there is a point that people don't work enough on : the POV !
I must say that finding a good POV can take me a lot of time...
You understand now, that I don't really have an Inspiration thing before I come on TG2...
Inspiration comes while I am having fun...
So I guess my advice will be : HAVE FUN (and maybe try something you never experiment before, it sometimes gives very good looking renders) ^^