A man is comfortable with who he is.
He has his own style and personality, accepts that not everyone will be okay with that and spends the majority of his attention on the people that are.
A man doesn't feel threatened.
He doesn't get all "testosteroney" when another man comes along who's stronger/funnier/smarter/better looking than him. He doesn't get possessive when his girlfriend spends time without him. He doesn't worry that other people have more friends or better jobs.
A man is calm.
He's slow to anger, doesn't freak out and doesn't act rashly. Everything he does is considered, and every mistake is a learning experience.
A man must be quick to both give and ask for help.
If a man is in a position to help someone out (and only then), he will. It doesn't matter who the person is - they could be a friend, a stranger, someone who bullied you in high school or a sexist/racist/homophobe. If it's someone who treated you poorly or is making bad choices, you can address that later. But right now they need your help.
In addition (and this is the biggest difference between my own rules for masculinity and the traditional media portrayal), if a man needs help, he won't be afraid to ask. He might be going through some emotional turmoil, there might be something he's not able to get on top of, or he might just need help lifting something heavy. In all of those cases, he doesn't try to shoulder the load himself. He doesn't think "I'm a man, I should be able to do this by myself." These days, it's much manlier to admit when there's things you can't do.
A man respects women.
This is an obvious one. But the problem is that everyone has different ideas for what that means. For me, it just means that when I meet a girl, I shouldn't let her attractiveness be the first thing I think about.
A man compromises.
Whenever he has to work with other people, he tries to work in a way that makes all parties happy, including himself.
A man doesn't whine.
Complaining is not an attractive thing to do. I'm not talking about in a sexual sense, I mean as a person. You turn people off when you complain.
A man shows a sense of responsibility.
This is the broadest of the rules as it encompasses the most. If a man makes a commitment, he sticks to it. When he goes to work, he does as good a job as he can. If he doesn't want to see a girl any more, he tells her in person rather than ignoring her calls. If someone needs his help, he doesn't ignore them. If there's a hard conversation he needs to have, he has it. If he's done something wrong, he admits it and apologises. Responsibility is a big concept and for me it's a very, very important one.
A man cares.
Making (or attempting to make) someone feel bad about themselves is a horrible thing to do. Just this week, someone at footy training called me a "pussy" for having a small water bottle. True story. He didn't realise that what he'd said was offensive, he just thought he was having a laugh. But it's this attitude that causes bigger problems in other situations. Think about every gay kid who felt like he didn't fit in because he thought the people around him would reject him if they knew. How about all the times that teenagers attempt to define themselves by belittling others, either unaware or uncaring of the long-term effects of their actions. Statistics show that 1 in 5 people are diagnosed with depression at some point in their lives, but how many people do you know that have admitted to having it? In my opinion, the most important trait that a man can have is the ability to empathise, understand and care about everyone else.