There are some things you just have to do for yourself... like going to the bathroom, like dieing (living), like finding your way trading.
For example, here are some basic ideological foundations of some simple systems. Follow the trend on retracements in trending markets, follow the momentum in trending markets, sell "overpriced" options/buy "underpriced" options, buy "oversold"/sell "overbought" chop markets.
However, no system is right all the time. Few are right much more of the time than they are wrong. And often the ones that work now will cycle in and out. It is what we do when the system doesn't work that makes us do harmful things. A system that works well can also cause dangerous trading career ending behaviors when it stops working. The old saw about fear and greed are career enders and all of these things are simply things you have to work through yourself.
Otherwise, it's like asking a scientist how to be a good scientist in 100 words or less.
YOU are going to have to put the time and energy in learning/testing a lot about everything, then throwing away what doesn't fit. You will throw away much more than you keep but you'll still have to go through the process because that is also where you'll develop your emotional control.