Trends are easy enough to spot and verify with various moving average indicators, from SMA or EMA or VWAP to crossovers, MACD, Bollinger bands, etc. If the moving average is slanted upward and the stock remains solidly above it, well, there you go. If it moves toward crossing below the MA, you have decisions to make. Often you will see a stock dip 1 or 2 standard deviations below the trend center and rebound back toward the mean and higher. Still in the trend, if it does that. But those dips are of course excellent times to add shares or to open a position in the first place. Buying when coming out of a strong dip allows your initial stop to be fairly tight, limiting your immediate downside considerably.
Keep in mind that a trend in one time frame might not be much of a trend in a different one.