I would've put this in the advice column, but the purpose of this thread is not to just give you advice on a specific subject, but rather a set of principles that will help one be more productive in life. I'm also expecting some debating.
When trying to be more productive, ask not "what should I do?" but ask yourself "what should I not do?"
You are already doing something every second of your life, what make you unproductive at what ever your goal is, is that you might be screwing up at something. So the key to productivity is not screwing up, and the key to happiness is productivity.
By observing these natural patterns, you can avoid misforrtune.
1. Never say to yourself, or even thing " I have a strong immune system. I never get sick." shortly after you get that thought you WILL get sick. I know this from experience.
2. Always say to yourself " I have a weak immune system" and ironically, you won't get any illness. It works for me, it'll work for you.
3. Never get to happy, or you'll forget something.
4. Never get full of your self. The moment you become full f your self, and swollen with pride, every one will be better than you. For example, if you say " everyone here is weaker than me", then everyone will actually become stonger than you and will be able to kick your ass.
[please wait while more natural patterns are being added, feel free to add your own.]