Always be aware of how you can help people. Wait an extra few seconds to hold the door for the person behind you. Offer to help people get their grocery bags to the car. You don't have to go overboard and risk hurting yourself (e.g. if you've got a precarious grip on something heavy, don't open the door for someone) but respect is paramount. True gentlemen don’t only focus on the women they like and ignore everyone else; being a gentleman is a way of approaching the world and all of the people in it, not just the ones you’d like to date. Be on the lookout for people who could use some help but who may not want to ask for it. The man carrying a tray of coffee would love it if you opened the door for him, but he may not ask. Be prepared to ask questions or make statements of courtesy, like "How was your day", "May I help you?", "Let me get that for you", or "I'll take care of that". Learn to speak slowly and carefully and to take the time to really talk to people in a polite fashion, no matter how rushed you may be. Whether you’re talking to your neighbor or the cute girl in your physics class, make an effort to smile, to be friendly, and to make interesting small talk about how your day is going. A gentleman doesn’t cut right to the chase, but takes his time getting to know people. Being able to make conversation is a sign of class and maturity, which are two important aspects of being a gentleman. Don't swear. Don't be vulgar. If it's too difficult to stop cursing all together, tone it down a lot. It’s just not gentlemanly to curse. If you do curse, you should apologize and try to keep the behavior from happening in the future. If you’re in a situation where you tend to curse more often, such as watching sports or driving in traffic, take extra care to watch yourself so you still come off as a perfect gentleman. Along with cursing, you should avoid any lewd or vulgar comments in general. And remember that what’s funny to you and your buddies behind closed doors may not always be appropriate for a girl you’re...

TL;DR in Chinese:
帮助身边的人。 礼貌交谈。 不说粗话，别显得粗鲁。 别以自我为中心。 别提起有争议的或敏感的话题。 尊重每个人。 不动用武力。