The Ethical Way of Getting Google Citations/Reviews?

Hey all, I am slowly but surely getting close to going for my first client in the offline "gig". Still being anal in making sure my website is good and finishing up on a few other elements before actually going out to get clients.

One of the questions I still have is in regards to getting reviews for my clients once I have them. Obviously that is an important factor in ranking their places page.

I'm not really comfortable on simply making reviews up, especially since I want to make sure I build a professional and credible business for myself. Going to a business owner and telling them one of the things I will be doing is making up reviews for your business so I can rank them better is not my idea of doing good business. What does it tell a business owner but that I'm not a totally honest guy and am I being honest with them in other areas?

My idea for adding reviews to a business who may not have a places page or other reviews anywhere else online already, is to enter honest reviews that they actually may have gotten within their establishment. Whether that be comment cards they have or some other in store system. I'm fine doing this as although I will be entering them myself, they are true reviews by customers. Obviously, I will incorporate a better system for them to begin using as well.

I'm wondering how those of you who are experienced with google places are handling your reviews? I understand the need for optimizing the reviews. In a few course and guides I've written, I have read suggestions straight up encouraging you to add fake reviews. In other instances from marketers who I respect and feel are upstanding, I feel I have interpreted "gray hat" methods to getting reviews which essentially are fake anyway.

Is there a general consensus as to approaching reviews? I don't mind walking a fine line, but as I said, I really want to establish a credible business while still being able to be competitive with those who may be doing it the dishonest way.