No matter how many careful observations you make as a mystery shopper, none of that will come through to the people who hired you if you don't write effective reports. At the same time, if you include every last detail, then the reader will be bogged down in minutiae. The trick is to find a balance between too much and too little. Use the directions given to you by the company in order to work your way through this challenge. If they ask you about how shopping feels at different times of day, then describe the people who served you, the time it took for them to notice you were in the store, and the phrases they said when they greeted you at the register. Remember names and the time you spent in line.
All of these are just preliminaries because the company wants to ensure that their employees are following appropriate directions they have been given about treating customers. The place where you can set yourself apart from your mystery shopping peers is by crafting a report that includes the details your company didn't ask you to describe but that might be helpful. Was the store clean? Where was it clean, and where wasn't it? Which parts of the store lacked certain features you felt were missing, such as mirrors? How was your overall experience affected by the layout of the store, such as the placement of specific products? In what way were your choices governed by the way the store organized itself? The company will want to know this because it spends a lot of time trying to figure out how to craft the customer experience. Ideally, nothing in a store is placed somewhere without cause.
The writing itself
In order to convey your mystery shopping experience, you will want to use clear, concise writing. Business Writing advocates the use of bullet points where appropriate. This can be a good choice because it neatly organizes discrete segments of data in a way that makes sense and is easy to understand. People follow bullet points more easily than the same information placed into a sprawling paragraph.
This points to another major area for practice. The College Board for AP English composition recommended that people take time to organize their ideas in an outline before beginning a writing assignment. While you are not writing an essay for an AP English exam, it is still worth considering outlining your main points. By writing an outline, you have a general sense of where your words are going, and you run less of a chance of making a jumble of sentences without a clear pattern.
It may help to read other people's mystery shopping reports to see what the overall structure is, rather than trying to invent your own.
Customer Impact provides a helpful note about style. Remember to be as objective as possible. Do not say something was "filthy," say "the floor had not been swept in many weeks." This is a good way to let your reader know that you do not take things especially personally. The same applies for good things as well. Instead of trying to explain, "The selection of winter jackets was fabulous," go into details about the different kinds of buttons and zippers available, plus the differences in lining, tailoring and materials. Describe one of your favorite jackets, but use objective terms: "I found a jacket I especially enjoyed because it was not available anywhere else. This jacket had a fur lining in the hood and clasps instead of buttons, along with an easy, functional zipper."
By remaining detailed, coherent and objective, you will continue to be a very in-demand mystery shopper.