tips: remember that ME's can be easily turned into solids and visa versa. Select the object and RC for options.
James' Tip: If you are not using sky illumination you may have trouble getting shadows looking anything but dark. Try GI (Global Illumination) and forcing FG (Final Gather) on (not auto) (more the FG than the GI). "It's the only way of achieving lighter shadows if you don't want the generic mental ray background (Sun & Sky setting). I also use the logarithmic exposure control over the automatic." You can see the Globe button lit up for GI to tell you it's on as the settings display whether it's on or off (no greying out functionality here). The interface design is rather poor on a number of the palletes in 2009 and I don't think it's really improved in 2011. Be aware too that these two settings will greatly increase your render times. For my day to day images I will not use them but if I am trying to render higher resolution and better quality for special shots I will turn them on, set the render to go when I turn the lights out and hopefully in the morning I am greeted with a fabulous image. If you are using RPC content then you may be warned to alter your Physical Scale setting. Be good if the defaults were set already. James thinks it's 1100. I thought I read 600. Oh! this pallet is raised by the command RPref . Sunproperties will open the sun pallete (I've alised it to Sun).
Other settings I know to mess with: If you have lots of RAM, you can try setting your memory limit higher than the default 1048. With 3.5Gb I have used 1800 but 2000 will crash. My home system with 2Gb will not get above 1600 (if I am lucky to get that). If you can get to 64bit and lots more RAM you will have better success trying to render larger images. At the top you can select from the presets. Medium will give you a reasonable quick render (5-20mins) but High or presentation turn on FG & GI and alter some of the other settings so only use them when you are ready for the final render. Of course the render time is greatly effected by what you are rendering, the materials applied, transparency, reflectively and the settings you have applied. When experimenting don't work on that 18 storey building! Try something small, even a few masselement boxes on a floor so you can get quick feedback.
Rendering is fun!! Go on. Have a go