Understanding a customers viewpoint - is all very well for the theory books and classroom meetings.

Just as important though is actually stepping out and looking at your business with a customers eyes. If you own a store then come out from behind the sales desk and see what the customers see, not once in a while but every hour.
I guarantee you will see a dusty shelf which needs wiping, a stray bit of litter in a corner, or a light fitting which needs fixing. Get out and about more often and spot things which let you down before everyone sees it.