I was a bit rushed on the list and 10 is a bit redundant. If I had it to do over, 10 would be:
Thou shalt remember the advice of the Japanese POW camp commander to Alec Guinness in "Bridge on the River Kwai", and that is "Be happy with your work." If you are not happy doing mystery shopping, it will reflect in the quality of your reports and will result in more trouble than solutions.
And really, that's the answer for any job, be happy with the work you do and you will discover that your life will be more enjoyable and relaxed.
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Have PV-500 & willing to travel.
"Answers are easy. It's asking the right questions which is hard." (The Fourth Doctor, The Face of Evil, 1977)
"Somedays you're the pigeon, somedays you're the statue.” J. Andrew Taylor
"I have never met a man so ignorant that I couldn't learn something from him." Galileo Galilei