A really excellent presentation from AU2011 by Jason Grant and David Light on how to leverage Revit for producing great graphics. Much of their advice is straightforward and many people will know pieces of it, but I doubt very many have been as systematic about it as what is shown in the presentation. Like most software for producing architectural graphics, much of the advice revolves around developing a consistent process that can be integrated with the day to day workflow and the curation of Revit families for all those little elements of presentation, like people, analysis lines
+ arrows and site elements. Anything to give life and depth without cluttering the graphic is useful.