Do some investigation about the place where you should hide the camera for recording. Select a place which allows you to record everything you want and make sure you allow enough room for the lens to capture the people, if they move around in the room.
Set the camera on video mode and select the lowest quality for recording video, as it will allow you to record video for longer period of time.
Make sure the lens is zoomed out completely, in order to create more room for the camera to record widely, if the subjects move around in the room.
Completely cover the areas which emit light from the camera. For instance, if you have an LCD or LED screen installed in your camera, then you will have to cover it completely. Otherwise, the subjects will easily recognise that something is hidden in the room, which is omitting light. Moreover, you should also cover the light which indicates that the camera is turned on.
Now disguise the camera by adding camouflage. For instance, if you are hiding the camera in the flowers placed in the room, then you can paint it in soil colour, or paste some flowers on its body, to make it invisible to the subjects. Similarly, if you place the camera in a basket full of papers, then you can paste a paper on your camera. You should also camouflage camera lens of the camera, if it telescopes out.
Now place your camera in your pre-selected place and turn it on. Press record and your camera is set to spy the scene.