How do you identify a valid trend?

I use EMA 50 on the daily chart. Price above EMA 50 = look for longs. Price below = look for shorts. Only trade in the direction of the higher timeframe trend.

Higher highs and higher lows = uptrend. Lower lows and lower highs = downtrend. Simple but powerful. Also check EMA 20 slope — if it is angled up, trend is up.