It is very old trade strategy. It is older than you :) Uses the RSI indicator. The RSI indicator has described Welles Wilder in the book in 1978. And all this is still profitable!
Step 2. If RSI is more than 50, then it is a uptrend and the long position opens. It is necessary to close a short position if it is opened earlier.
Step 3. If RSI is less than 50, that is a downtrend and the short position opens. It is necessary to close a long position if it is opened earlier.
Well is suitable for the market of cryptocurrencies. Well length from 3 to 7 approaches. Don't use length 14 because for cryptocurrencies it is too much. Cryptocurrencies it is very volatile market. You can also use the RSI indicator which is built in on TradingView.com.