TA can be a hobby, or serious business.
Increase in ratio of success comes with experience.
We may use various systems for fun, but sub-consciously, we know one of them is better. Over repeated use, we put in our faith in that particular system, knowing its weaknesses too.
So, knowledge or exposure to multiple systems, focus on a comfortable system, faith in it allowing leeway for its weakness, can help a trader increase ratio of winning trades.