I use a very non-emotional system that has made me great profits since 2017.  I'm generally long.

I only play in ETH and BTC

When the price hits a new ATH or pops up 30%, I sell 30% of my portfolio and pay my short term gains tax separate savings account
When the price goes down 15% I start buying in 30% increments the amount above every 5% down using the money from above until hitting 25% down
When the price goes down 30% or more I buy using new money
If none of the above conditions happen I hold and wait and ignore the news

Bluelogic