What is your limit? Many times people, especially common people, will only go as far as they are required or until they hit their limit. This has always been an obstacle that i have wrestled with especially with my employees, how do you get them to go that little bit extra?
As a beginning triathlete I found myself falling into that same trap. I would exercise at my PE threshold (perceived effort). I thought I was working hard and would just push myself until I "thought" I was exerting enough effort. In December I decided to compete in my first Ironman event, a grueling 2.4 mile swim, 112 mile bike ride and a 26.2 mile run. So I hired a coach.
The first thing my coach taught me was to gauge my effort off of my heart rate. She taught me my heart rate zones, I bought a monitor and got to work. She would give me specific heart rate zones to work in with the strict warning to stay in those zones. I soon found myself working harder than I ever had before and I was always pushing the zones to their limit.
Most clients you will encounter are the same way, if you leave them with unlimited options they will usually do just the minimum they feel comfortable with. However, by setting limits and restrictions you will find that your clients will push the limits as far as they can. It is human nature and it can put more money in your pocket at the end of the day.