Open Discussion: Planning Stages

After a full year of classes that revolve around the planning and execution of artwork, of countless thumbnail images and sketches, of small scale mock ups and redesigning even before the work has begun, I can't help but think our collective hobby doesn't do nearly enough pre-project concept work!  That's not to say I haven't seen some really long concept threads over on DakkaDakka from time to time, with well over ten pages of concept development and nary a miniature to be found!  But I feel that even half of that dedication to ideas isn't the norm.

In my own hobby adventures, I freely admit that most of my armies roll around in my head for a single 'OMG this would be cool...' session at the game shop or online with a friend or two.  The only force that really found a good amount of idea development was my Sons of Medusa army which lead to some good ideas and a few concept miniatures to help develop the ideas decided upon.

So I toss this question out to you:

How much time do you usually spend developing an idea or army before you get right to executing it?  Are you the type to get right to work with the slightest thought?  Or do you spend hours agonizing over the smallest of details?

Comment, reply, converse!  The floor is yours!