I usually sell in 3 orders: when price grow by 50% (16.5% of bought amount),by 100% (16.5% of bought amount) and by 150% (16.5% of bought amount) + hold 50%.
Nice plane for exit or profit realization. I also have my own plan but my plan depends on the prices. For example, for ether:
In $1,250, 25% of my portfolio.
In $1,750, 35% of my portfolio.
In $2,500, 20% of my portfolio and the rest will be watched by me.