Camera placement determines whether you get footage that identifies someone or footage that merely proves something happened. It matters more than resolution, and it is the thing people most often get wrong.
Cover entry points, not open space
Burglaries overwhelmingly begin at a small number of predictable places: the front door, the back door, ground-floor windows, and any side gate or garage. A camera covering an entry point captures someone at a known choke point, at a predictable distance, facing a predictable direction. A camera surveying a large open room captures small, ambiguous figures crossing the frame.
Mount at face height, not ceiling height
The instinct is to mount high, out of reach. The problem is that a high camera looking down captures the top of a head and shoulders — which identifies nobody. Around 2–2.5 metres is the usual compromise: high enough to be inconvenient to grab, low enough to catch faces. For indoor mini cameras like the XCAM Nano, shelf height often works better than any wall mount.
Never point a camera at a window
Two separate problems. In daylight the camera exposes for the bright window and everything indoors becomes a silhouette. At night, infrared LEDs reflect straight off the glass and wash out the entire frame. If a camera must face a window, disable night vision and rely on room lighting, or reposition so the window is behind or beside it.
Think about what is behind the subject
A camera with a bright light source behind the area you care about will underexpose the subject regardless of specification. Aim so that the background is a wall or a dark area, not a lamp, a doorway to a bright room, or direct sun.
Wide angle covers area; it does not add detail
An ultra-wide lens such as the 155° on the XCAM Cube covers a whole room from a corner, but it spreads the same pixels over more scene, so anything far away is smaller in the frame. Use wide angle for coverage of a space and a narrower lens for a specific approach you want detail on. Two well-placed cameras usually beat one very wide one.
Where not to put a camera
This is a legal question as much as a practical one. Bathrooms and bedrooms used by guests, lodgers or staff are off-limits in most jurisdictions, and so is any area where someone would reasonably expect privacy. Pointing a camera into a neighbour's property or a shared hallway is restricted in many places. Audio recording is regulated separately and more strictly than video almost everywhere — a camera that is legal to install may not be legal to run with sound.
Check the rules that apply where you live before installing. If your concern is the reverse — being recorded somewhere you should not be — see how to check a room for hidden cameras.