Elliot Waves is not a tool you use solely on its own, but combine it with other tools and signals. I mostly use EW based on current trend.

In a downward trend it will be opposite of an upwards, you keep getting lower lows in waves too. The trend is your friend, also counting the waves.
Trend direction changes can be spotted counting subwaves but I think a lot of experience is needed to act correctly in these situations, as we tend to seek our most used patterns first.

Also combine the EW with volume and macd for direction changes, and finishing of waves and patterns. With Elliot waves, trend, volume and macd your predictions can be pretty accurate.

The corrections can take a lot of directions, and 36 of them are described with EW. The question is picking the right one, also need practice and experience to do. And practice opportunities in downward trends are scarce in crypto nowadays.

You cannot just do a wave analysis for the next 6 months and trade by that chart over time. EW predicts price moves ahead, and for precision and confirmation you need also the latest price moves in your analysis. It is when you update the charts you can get those AHA moments where you spot the trend change.