The answer is:
- Trade management methodology
- Risk management system
- A methodical way to enter the market (even if its a coin toss)
My system of trade management is fairly mechanical. I prefer fixed stops and a fixed scalp exit that is twice the stop size. Some discretion may be applied for any additional contracts. They may be held until a price target is hit such as high or low of today or prior day, or the trend terminates (by breaking a trendline), or a climax bar or simply when the profits are too large to be left on the table. The first step in creating a trading system therefore is to determine an acceptable stop size. If the stop size is too small, you will probably be stopped out before reaching twice the risk. If your stop size is too large, it may never reach twice your risk. Somewhere in between is a band where stop size is acceptable.
Risk management is also pretty simple. I have maximum loss limits per trade (stop size), and per day (maximum number of failed trades) and in case I run into unexpected price action, I will also have amortized loss limits per month. I have posted extensively on risk management and those rules are universal regardless of what you trade.
There is a broad choice of ways to enter the market based on indicators, price action, support and resistance levels and possibly countless others that I haven't even heard of. I have the strongest confidence in price action, having tried many others which resulted in utter failure and bafflement.
However, for the purposes of stop size determination, I may choose a mix of random entries and price action. Once stop size is determined, I'll only trade price action.