It's all about process
If you did miss it, its a brief piece about Michael Mauboussin, head of Global Financial Strategies at Credit Suisse and his writing on the skill/luck spectrum. He stresses the importance of process (more at that link above, or just go straight to his book):
How do I know if my process is any good?
Number one, has it worked in the past and is it economically sound?
Number two, I think of good processes as having three essential elements. Element one is analytical: having an ability to find situations in which you believe something the world doesn't believe and in which you have a good foundation for such a belief. The second is behavioral: we are all subject to behavioral mistakes and cognitive biases. Are you aware of those things and are you taking steps to manage or mitigate them? The third, which is less true for individuals and truer for organizations, is what I call institutional.
I have a lot of time for Mauboussin, checking out that link above is a good start on his work.
I'd also point out that you don't necessarily have to agree with all he writes.
Take this, for instance:
having an ability to find situations in which you believe something the world doesn't believe and in which you have a good foundation for such a belief
What if, instead you have an ability to find situations in which you believe something the world does believe and in which you have a good foundation for such a belief
Trading on the same side as 'the world' is often a very good thing - having others buying what you are buying (for example) is a powerful tailwind in your favour, a 'trend'. Sure, trends end when everyone is the same way around, but until then its your friend.
Trading losses? Just do the opposite! (And why that probably won't work)