Blender : Modelling with cross sections
By Olivier Saraja
S  t  e  p   5 :

Using the G-KEY, the R-KEY, and the various points of view accessed by the NUM-7, NUM-1 and NUM-3 keys, move the camera inside of the landscape, but try to let it next to its border. Choose a place close to the floor, in order to add dynamism to the view. Check the good placement using the camera view (NUM-0 key) and the shaded view (Z-KEY).

IWe now have to set some good light sources. Place a lamp in front of the camera at a good height : SPACE>ADD>Lamp. With the R-KEY and G-KEY, orient the spot in the three different views.
You can then press the F4-KEY to get in the Light Buttons. Activate the Spot Button and give it an angle of 90° with the SpotSi cursor. Activate the Halo Button. Play with the color cursor to obtain a warm but soft light : R:0.950 V:0.950 B:0.9. Set Energy to 0.800 and HaloInt to 1.200. Select the Spot if it isn't pink anymore, then activate the Snap Mode with SHIFT+S. Choose Curs->Sel. Add another Lamp : SPACE>ADD>Lamp. Give it a Distance equal to 50, to be sure it will illuminate all the scene. Give it the same color than the Spot : R:0.950 V:0.950 B:0.9.

Tips : make sure that another Spot (located at the exact same place than the first) points directly toward the camera, in order to achieve the best illusion possible of a sun. Reduce a lot the angle of its cone (low SpotSi).
If you render now your picture, you'll see a feeble sun, not satisfactory. You can add a last object to your landscape, at the exact location of your two light sources by using SHIFT+S and Curs->Sel when the Spot, for example, is selected. Press SPACE>ADD>MESH>Icosphere. Confirm the number of subdivision, this is not a critical factor. With the S-KEY, lower the size of the Icosphere to something like these values : Sizex : 0.100, Sizey : 0.100 and Sizez : 0.100. In the Material Buttons (F5-KEY), assign a new material (call it Sun, for instance) to your Icosphere. Activate the Halo Button and lower the HaloSize to a low value, just like 0.2. Exit the Edit Mode by pressing the TAB-KEY.