in my vast experience in dating i have found that i really prefer a man who is polished. simple etiquette or lack thereof can be a deal breaker. no nose picking and no running one's fingers along ones nostrils on a date. no teeth picking on a date. don't put one's entire hand into one's mouth to pick one's teeth during a date. chew with one's mouth shut.
another big no-no is when someone is disrespectful to the wait staff at a restaurant. aside from an obvious lack of derech eretz being rude to the wait staff increases the probability of one having one's food spat in before it reaches the table.
these rules should be obvious but apparently they aren't.