There are little bits of information that people will give you that will help your opportunities but often the best information is too valuable to get for free. Often that information is not for sale either. It's given out of respect.
Respect is a lot easier to lose than gain and so if you want to get good tips, always be trustworthy and always be generous. That's probably the best place to start.
I think that the best tip that I found on Namepros was to reject at least 90% of the domains that you consider buying. (Spend more time looking and learning and less time buying)
The other thing that I always think is that you should base your decisions with your head, not your heart. There is usually an emotional attachment people get with domains. If you let this take over, you can pay too high a price for a domain or refuse a good sale price on a domain.
Lastly, stick to your budget. Don't spend money you don't have and always have emergency money for unplanned expenses. Always assume that you will pay for at least 3 years registration fees when buying domains.