Use a position inferior or equal to 2% of your capital.
Have a defined trader profile.
Be aware of news to see where a security might become volatile.
Diversify your portfolio (3 securities minimum is recommended)
Have a robust money management strategy.
When trading trends, make sure to set your indicator settings such that you don't catch retracements in the trend, this can often be achieved by using higher settings.
Don't keep a loosing position that exceeds your loss aversion.
Don't use aggressive position sizing strategies such as martingales.
Don't make impulsive trades based on non educated guess.
Avoid trading lower timeframes where frictional costs are more significant.