I have learned how important position size is and how to begin to increase once you have achieved consistent profitability on the smallest stake possible. Scaling in and scaling out to improve your theoretical average is something true pro’s do. Letting your winners run means moving a position to break even or profit and add another piece to build a pyramid. Scaling out at a pre-defined point is wise and brings a lot of comfort e.g. ES at 4 points profit. You lock in profit and let a small portion run.
The first step is to develop a deep belief in your methodology and your ability to be consistent. The way to do this is by backtesting and by being consistent. Once you have achieved that, increasing size a tiny step at a time is the way to go. The first couple of steps are the most difficult because if you were trading 1 lot and are now trading 2 lots then it’s a 100% increase. If this is difficult, go back to SIM and validate the size as CP and then go live, repeating the SIM to LIVE steps each time you increase you size until the increase would not be so large a percentage.