When ETH will be at its peak : how to behave ?

Hi everyone, As 2021 will be a very good year for us, I am wondering more and more often how I will behave when it is gonna be the time to take profits. I entered the ETH market in January 2017 and as a newbie, I didn't know how to take profits from the 2017 bubble. I just hold, which is in a way, a good thing...I guess... 🤔 I leave in France and here, the tax applied on the cryotocurencies benefits is 30% (which makes me sick !!). So, I think that selling everything for € is not a good strategy if you don't need the money RN (which is my situation). So yeah, I don't need much money but still, I would like to enjoy some profits. I was thinking to sell 60% in €, 20% in USDT (no tax) that will be reinvest later when it will be down, and keeping 20% untouched. What strategy do you think is the best? Do you have an experience to share ? It is a bit scary when you don't use to deal with so much money (well I will never be a millionaire but it is still a lot of money). Thank you for wise advise 😁 (And sorry for the mistakes in English)