I agree with your suggestion not to hold the coins too long because we do not know how good their performance is in the future. But if that is about bitcoin, I am sure we can hold it for a long time as bitcoin already prove to us that bitcoin can give us a big profit in the future. But if that is a new coin, we can hold it for some time and sell it at once when the price increase so high because almost many new coins or tokens will have their time to soar higher someday. But be careful, the new coins will not always increase so high and give you the profit.
We must be wise in classifying investments in top coins and new coins because both cannot apply the same trading method, except for new coins that have received support from mega projects from the beginning of their development until the project is successful, some of my investments are embedded in new projects and provide huge returns if invested in the right new projects.
I am not too often invest in new projects so I do not know how long that project can give a huge return to you. But what I observe is when the new project list on the major exchange, that could be the time to give you a huge return. But that will not always happen to most new projects. While the old coins can increase anytime because they still have power and a strong community but they are waiting for the right time to increase. Sometimes, the old coins can give you a huge return as their community can give them more power to increase.