Think of something that you find good or bad, ugly or beautiful.  On the surface this would be a subjective thought.  But if you dig beneath the surface thought you can define the components of any topic.  Start by asking the question: “why?”

Ask yourself what aspects of this thing you can define or measure that makes you determine whether it is good or bad, ugly or beautiful?  If you are talking about a house, perhaps you are defining beauty by: style of house, window size, color, materials, location, etc.  With each element, you can dig further into your definition of beauty by putting guidelines or measurements to your definition.  For example: I find the most beautiful window size to be no more than 4 ft height per every 12 feet of elevation.

Once you get the aspects defined, the statement becomes objective and makes discussion or negotiation with someone else much easier.  You might even find that arguments go away completely.