My addition (6): observe others, be inquisitive about other people. This will not only help you appear smarter to others (believe it or not, there is such thing

My addition (6): observe others, be inquisitive about other people. This will not only help you appear smarter to others (believe it or not, there is such thing as behaving/appearing smart), but will also help you with networking because (a) people respond positively when someone displays genuine interest in them (well as long as you are being nonthreatening) and (b) smart people tend to seek out others like them.