Where do you draw the line?

I respect my customers' personal marketing tricks/techniques and want to honor them. In order to do that I need to draw a line firmly in the sand as to what IS personal marketing and what is public marketing? I am often asked for advice about how to market a home. Obviously you have postcards, flyers, internet marketing, etc. That's common knowledge. That's not protected marketing in my opinion. What IS protected marketing would be custom verbiage, perspective, and branding. What are your thoughts? Where would you draw the line?