If you are willing to accept total responsibility for your investment results, you will realize that you are the most important factor in your trading or investment success. If you have done that, you are way ahead of the crowd.
I once had a call from a gentleman in England who had been working with my home study course. He said, "I've been working through the course for over six months. It's helped me realize a lot about myself, but there is one thing it hasn't done. It hasn't given me a positive expectancy system." The ironic thing about that statement is that I had not attempted to give a methodology. There are several reasons for that: 1) If you want to be good, you must design something that fits you. That only is possible if you design the methodology. 2) Psychology is far more important than methodology. In fact, psychology is part of methodology. For example, when we attempt to help people develop a reasonable method that works, they resist it strongly because they have so many biases that keep them focused on the wrong aspect of trading - areas that have nothing to do with success. And it is very difficult to show them the correct direction.
As a result, the best thing you can do for yourself to increase your income from the market is to determine how you are blocking yourself. This should be done at two levels. Whenever you develop a trading business plan a great deal of that plan should have to do with introspection. Take a look at all of your beliefs. Are they useful beliefs or do they hinder you in some way? What are your strengths and weaknesses? What about you can't you see clearly because you are part of it? You should look at doing this sort of assessment at least once each quarter.
The second self-appraisal you need to make is at the beginning of the day - and perhaps even hourly throughout the day. What's going on in your life? Are you ready to face the markets? How are you feeling? Is there some sort of self-sabotage surfacing in you? For example, are you starting to get too confident? Are you starting to get too greedy? Do you in any way want to override your system? The best traders and investors are constantly doing this sort of self-assessment. If you want to make money in the market, then perhaps you should start doing the same.