Use high quality IBL whenever possible - the Physical Sky/Skydome solutions are usually too homogeneous to give the subtlety of real-world environments in your reflective surfaces.almost nothing is uniformly smooth in reality. Textures should be a part of nearly every material - even if it is a simple metal it should still have a bump and/or roughness mapping texture (not to mention anisotropy).The wood is nearly white or yellowish-white and yellows under influence of air and light. So use/create MXM materials whenever possible - the current SketchUp plugin can only produce 'quick-and-dirty' simple materials for the most part. The sapwood and the heartwood are hardly distinguishable. Materials are a huge part of success in Maxwell - probably the most important thing really.Any geometric details you add to the model Maxwell will make use of. Pay close attention to how the objects exist in the real world - if they have have rounded/beveled edges make sure your model does too.There's no one thing that can make a render more realistic - it is more a combination of many small things that will make the difference.
