^ To tell you honestly day trading is very risky and there is no right or the best strategy that we can consider as accurate to use all of them are just predicting the market price. In my own, trading in a long term could be the best way to apply such a strategy because there is more time to think about when BTC prices move and you can set targeted profit before selling them. Buy low and sell high is the best and the safest strategy for me but like I said, this is not applicable on day trading or short-term trading.
There is no well defined strategy in investment that is best for investment. A strategy that is profitable for you may not be suitable for me.
If you talk about day trading then the window of good strategy shrinks further as its more about luck then what strategy you are following. Buy low and sell high is strategy that is easy to say buy very difficult to follow. As we dont know whats the bottom low where we must start buying.
IMO hodling or long term investment is the only strategy that is both secure and profitable.