It is always a good idea to have a safety fence and locking system around the pool, but you want to do one better than that. Have safety signs that warn about drowning and trespassing can deter some people, though not all. It may help you if something were to happen and someone takes you to court. You also want to think about safety signs if you have some unusual things around your home an property. Water is always a danger, so put some around ponds, lakefronts, and small creeks. You should also think about hazards that may stop or trip someone if they were walking through your property. If you have an area that you deem to be dangerous, use the no trespassing safety signs that you can find just about anywhere to deter people from walking through the area.