Map Makers - What's your approach?

To the Veteran and even newer map makers, I have recently installed the SDK and I am finally taking the plunge into map design. I have gone over the basic tutorials and read through danh's helpful guide. I am curious as to how others approach the level design.



Mainly:

What do you design / create first? Terrain? Spawns?

Do you use the native terrain editor or import from third party program?

Do you make changes to the elevation before laying out a material for the terrain?

Is it best to copy/paste from stock maps or pull each item from the content browser as you go?

Do you layout static meshes before pylons/lighting or later?

Does any of this really matter or is there only one good approach to making the level?





Seeing how the editor gives you a blank slate to start, I can really appreciate that we have so many well created and well playing maps. Any input or advice would be VERY much appreciated.