My top pick for tips on how to catch cheating is this book by Sarah Paul

The Techniques of How to Catch a Cheating Spouse

Do you suspect your spouse is cheating on you? If so you need advice about how to catch a cheating spouse without having to hire a private investigator. There are two main ways of discovering that your spouse has another lover - you either catch him/her in the act or you have suspicions that lead you to collect evidence of an affair. In most cases, the discovery is accidental, such as in coming home from work early to discover your spouse and the lover in your bed. You may decide to surprise your husband while he is on a business trip only to find that he is sharing his room with his secretary.

When you have an intuition that your spouse is cheating, you should go with that feeling. There is no one sign that points to infidelity, but rather a combination of little things that start to add up. It also happens over time and you start to realize that things are different between you. Rather than make accusations right away, you have to start being more aware of these little things and taking additional steps to try to find out what is actually happening to your relationship.

Surveillance is the most effective method of catching a cheating spouse. This can include little things such as monitoring the phone calls that come into the house. Check for unknown numbers that call several times and then use a reverse telephone lookup to find the name and address of this person. Since most people use cell phones these days, you may have to get an opportunity to look at the caller’s list on your spouses cell phone. Then when you do have a name to start with, you can devise a way to bring this name into conversation to see what reaction you get.

You can start keeping a journal of your spouse’s activities to find a pattern. This is especially true if your spouse has recently changed the routine or schedule. You should record names, dates, places, people and excuses to give you a complete look at the evidence. Then you can compare these dates with records such as back statements and credit card statements to verify that he/she was where they said they would be. You do need to have this record so that when you start to ask questions, you can check the answers against the story your spouse gives you.

Plan unexpected visits to where your spouse said he/she would be. You shouldn’t make this obvious because it will only arouse your spouse’s suspicions and make him/her extra careful. If your spouse says he has to work late, drive by the office to see if the car is in its usual parking space. He may not be alone, but at least he is where he said he would be.

One of the best ways to catch your spouse cheating is to purchase a monitoring system for the car. This could be a listening device that you can install under the dash or even in the trunk with the microphone hidden in the car. You will then be able to hear the conversations that take place when he is on the phone or has a passenger with him. Then you will have the evidence you need to force a confrontation.