The caution about wearing jewelry always stands out for me when people say that is the same advice as when at home. We live in NYC and my wife is very comfortable wearing her jewelry wherever and whenever she wants. We have lived here our entire lives and never had any problems. Although there are tourists that are told not to wear their jewelry in NYC or think it's unsafe to do it. I think it comes down to standing out as a tourist aka target and your own level of comfort in your surroundings.