I guess it depends on what cameras you have. I am going to assume that your model cameras did not come with IVS built in. If not, I would record continuously and motion at the same time. You will need to go into each camera, through the recorder, and enable motion detection. Then set up your regions for motion detection. Mask out any trees or stuff that moves all the time like a road with constant traffic. You will also need to play with the sensitivity so that you don't get every spec of dust that floats by. When you are recording motion, expect more movement when its raining or your sprinklers are going, or a spider is building a web around your camera all night, etc.. Changing the cameras to ones that have IVS built in will greatly increase the accuracy of detecting a person. If this is an option for you, make sure that your recorder supports IVS functions. These will be present in the Event tab where motion detection is configured.