What's a good selling strategy that maximizes profits and minimizes risks? How to sell as close to ATH as possible?
Best way is to move with the trend. Pick your assets and be in them when they go up and move out when they are going down. Profit should be when you are completely happy that you have reached that assets full potential, or if you are happy taking money out as profit to invest in other assets to achieve the same goal.
For example, check out this with Ethereum.
Use the daily timeframe, EMA 34 (YELLOW) is usually pretty good. When the asset is above (it acts as support) if below (it acts as resistance)
You have huge periods of accumulation and huge periods of growth in value. (Accumulation is moving into a stable currency and rebuying back lower = more ETH)