1) 1st identify if u are in a trend. If you are in a trend, trade with the trend.
2) 2nd, there is no way to tell before the fact that a trend will break. Obviously some people will try to pick tops, eventually they will be right but hopefully before they lose their entire account.
3) However, there are ways to tell when a trend has in fact broken and then trade with the new trend. If the trend was up, then seeing a LH after a LL. A full candle breaking below a support level. A triangle or trend line break.
4) Note you can have a false breakout if the trend is pretty new that for example will trap someone. It also depends on FA and if the news was really good that made an uptrend. For example, believe it or not Trump beating Biden will move stocks higher. A Biden victory will move stocks lower. This does not mean I support Trump since I just need to right on direction and I don't care if stocks go up or down as long as they do go somewhere that I can follow.