I have been using a small mirror for a couple of years now, with a neighbor who sometimes becomes belligerent and aggressive for no reason. I put the mirror in the space between the storm window and double-hung window, facing the neighbors house. It immediately made a huge difference, and I think that at some level this neighbor may even understand why it is facing his house. I also have neighbors who in the past have played music too loudly. I handled this by putting a radio in the window, facing outwards, playing classical music quite loudly. The radio could not be seen since it was in an upper window, but they got the message, and I let off steam. Good luck. Hally