I think worrying about how you praise somebody in an effort to essentially albeit non-confrontationally argue and change their perspective is an effort to be altruistic in your own actions and trusting that your child will grow healthy naturally.
Take years, train the attitude you want to see by by getting them to participate in events or actions where there will be at least a minimum of success on a scale of 1-5 in the area of risk-taking. Then you simply notice what happened and talk about it.
Mix up cajoling, with explaining, with commiserating, with pride and optimism. In other words you're already doing what any parent can do.
I think, and this may be childish, but I thinks kids should be allowed to "do it wrong" to an extent. If he's not showing good work ethic in some activities I think he should be allowed and encouraged to still participate. Some things some times you have to give your best on, but I think sometimes you can participate in something you don't always have to give your best on. Sometimes it's enough to just show up. We know that smart kids feel strange when they struggle, but we're told that most other people feel that struggle most of the time most of their life. (Not really sure if that's true). On the same hand it seems that not all the other people are try their best at everything they do, and many seem fine with doing less than their best and still participating.
"What's the biggest room in the house?"
"Room for improvement."
