1. Stationary surveillance: Sitting there waiting for something to happen as you observe a stationary establishment.
2. Mobile surveillance: When the subject of the investigation leaves the area either on foot or in a vehicle meaning you have to follow.
3. Video surveillance: When you are recording video, no sound, of the subject of the investigation.
4. Covert Surveillance: when you enter a facility that is open to the public and there is no general expectation of privacy and obtain footage through covert gear. Common tools are a key fob, phone, button camera.
5. Neighborhood Canvassing: This is a fancy way of saying a pretext. You make up a credible story as to why you want information about the subject without stating that it is about them to ascertain details as to residency, vehicles driven, active times and so on.
6. Reporting: This is what most investigator hate but it is a requirement of the trade. If you cannot speak or write grammatically correct English, this is not the field for you. For those that can, the company that hires you will explain how to write the reports the way they like to see them.