Start with friends and family, after all they will be your best, and worst critics. As for the public, go slowly. Try and get something hung in a local pub, or restaurant. Put some contact info on it, and listen to their responses.
And I know just what that person ment. The exhibition that I have been told was my best was one where I felt I needed more time to work on the images as I felt I hadn't got my concept fully realised. (and I am still working on it....)
When bankers get together for dinner, they discuss art. When artists get together for dinner, they discuss money. Oscar Wilde Blog fp4.blogspot.com