I always say 'trade with the trend, not against it'. There are some circumstances where you want to trade against the trend such as market extremes, when you see heavy divergence on the RSI etc... However mostly ... trading with the trend is a winning strategy.
Right now BTC is in a downtrend on the 4-hour scale.
A downtrend is characterised by three things:
Lower highs
Lower lows
50 Moving average trending down
An uptrend is characterised by
Higher highs
Higher lows
50 Moving average trending up
For me, the point where BTC entered a downtrend was 8,800, when it made its first lower low. At this point the 50 MA turned down as well. This is where I cashed out of long positions and started to go short.
If BTC can make a higher high, we re-enter an uptrend. If not, we are going down... There can be some whipsaws using these techniques but the longer trends always pay for the whipsaws.