In my new job I am spending a fair amount of time data modeling specifically around Data Warehousing Data modeling. The team I work on are pretty committed Kimballists meaning we generally follow the dimensional modeling principles outlined by Ralph Kimball. As with any programming methodology (and likely any methodology period) there is a fair amount of gray area. That is where both experience and "gut feeling" come into play in making decisions on how to model certain things that don't fit the philosophy very well or perhaps fit multiple parts of the philosophy.
What has surprised is why there aren't more forums out there to discuss this! I can go Google C# of Java or Oracle or perhaps better examples would be Agile Programming or Test Driven Development and find a host of forums to look at, but data modeling or dimensional modeling forums specifically seem to be very few and far between. It surprises me after all these years of Kimball espousing the philosophy etc... that he hasn't made available forums for discussion to happen etc... It would be fascinating to pose problems and see the community's opinions and to respond to other's questions as well. Sounds like a project in the making! Anyone interested or know if a good place already exists (not sense reinventing the wheel!)
