Aspects of Mystery Shopping:

Anonymity

A good mystery shopper is always anonymous. A mystery shopper should be able to visit the same location a number of times without being detected by the staff. Mystery shoppers do not take forms on the premises with them and do not take notes when they are visible during their shopping time.

Reliability

A mystery shopper who does not reliably complete assignments is of no value to our company and will quickly be eliminated from our shopper pool. Of course, we realize that occasionally a situation arises that prevents a shopper from completing an assignment they have agreed to take. Reliable shoppers contact us immediately to inform us of the situation. Reliable shoppers submit their reports within the deadline after completing the shop.

Accuracy

Forms must be completed in detail. Areas cannot be left blank, questions cannot be overlooked. Your written observations must agree with the way you scored questions. If we have to contact you to ask for missing information or clarify what you have submitted, your payment may be reduced and your status as a shopper could be jeopardized.

Review

After you submit your shopping report (also called a Quality Audit), it is reviewed by an editor, who checks it for completeness, detail, accuracy and to be certain that it meets the high standards of Secret Shopper®. You must be accessible to an editor during daytime hours and available to discuss your report, if necessary.

Remember it is a job and they should be paying you. Again it is a job so you do need to train and fill out forms. You do not need to be certified but I do recommend it. Mystery Shopping Providers Association's is the place, you will learn from the training and it will make you look more legitimate to mystery shopping companies. There are 100's of companies, some are legit and some are not. I only know about the ones I have worked with. All of the links I have posted are good companies. If they have work for you, that is up to you and the company. You will not get rich doing this but it can help a tight budget and enable you to go to fine restaurants when otherwise you may not be able to.
I can not guarantee a job, but I can give you tips.

Tip 1:
Be honest, tell the truth

Tip 2:
Give Facts, not opinion, do not say the worst service, but say I waited 29 minutes

Tip 3:
If you take a job, then do the job, do not skip it for what ever reason.

Tip 4:
Keep it a mystery; do not give yourself away as a mystery shopper.

Tip 5:
It is a job, you might get a free meal or free groceries but they are not really free. You need to fill out a report in order to get the item or service.

Tip 6:
Again it is a job but have fun, you can make changes. What you put in the report can let the company improve.

Tip 7:
Keep all receipts.

I may add more later but I think all of these tips will help you in your quest to be a mystery shopper.

This is the type of thing many companies are looking for.
This is an example of a mystery shop that I did. You need to be able to describe what happened. This was much longer and I just posted a portion from my original shop. In order to give people and idea of what is needed. It can take a lot of work, remember mystery shopping is still a job.

For our appetizer, we ordered the Dunkin Onion. The presentation was ordinary, with the onions placed around an oval shaped bowl, which had the white creamy dipping sauce in it. They were fried, and slightly overcooked, they had a burnt look to them. The temperature was slightly too hot, and we needed to let them cool off before tasting them. The white cream sauce was cool and mild. It tasted like a sour cream sauce, and this sauce was a good combination with the onion flavor.
Both of the entrées were a pasta dish. They were presented very plain in a deep round white ceramic dish, with no type of garnish or bread.
The first pasta entrée was the Thai Pasta dish. It had mild spicy peppers in it, and crisp snow peas, corn, and water chestnuts in a bowl of spaghetti pasta. The sauce on it was thick, hearty and spicy, but it was not too spicy. This dish had a nice mixture of flavors and textures.
The second pasta entrée was the Chicken Broccoli Penna. This dish had chicken, broccoli, and mushrooms swimming in a creamy, white wine sauce. It was cooked to perfection, but most of the pieces of broccoli were smaller than the mushrooms. It only had two large chunks of broccoli and the rest were small crumbs. This dish had a enjoyable mild flavor.

We ordered the fried Cheesecake for dessert. We ordered it to-go. Although it was in a to-go box it still had a wonderful presentation. It was sliced in ½ on put in a tower with chocolate sauce drizzled on it, and two dollops of whipped topping. The ice cream was in a separate container. We ate it right when we got home. It seamed to melt in our mouths. The crispy and cream textures blended well, and the chocolate sauce added a sweeter flavor to it, but not too sweet. We would recommend this to anyone.
We both ordered ice tea for our beverages. It was served in clean glasses and they were filled all the way to the top, with a slice of lemon. The drinks were served cold, and were what we expected. All refills were as good as the first.