Lighting and rendering are the most important factors, assuming your models have reasonably qualit MATs and shaders.

I'd back the advice to leave GC on and lower the light settings.

Choose either IDL or AO. You don't need both. IDL mimics real lighting better; AO has a distinctive look many people like. Your call.

Always favour raytracing with raytraced shadows over depth-mapped shadows. Use the shadow blur radius to soften the edges of shadows.

Use manual rendering settings, rather than the automatic slider. It's more efficient.

Pixel Samples: 3 for a preview, 5 for a final image without depth of field, 10 for a final image with DoF. This has a major effect on the 'crispness' of your images.

Min Shading Rate: Lower than 0.2 is overkill for most textures.

Raytrace bounces: 2 for simple reflections, higher for special cases (multiple mirror bounces, refracton etc).

Depending on your scene and its complexity you can lower pixel samples, turn displacement and smoothing on or off.

If your mdels are still looking pale (rather than blown out by overlighting), it's probably easier to postwork the colour levels.

Andy Staples
The Penultimate HârnPage -- www.penultimateharn.com