Experience in crypto currency has taught me never to be in an hurry to buy a crypto currency token or to join a crypto currency trade pair; The same applies when you are to sell a coin or close a trade pair; never be in a hurry. Sometimes before investing huge; you can buy as low as 5-20$ and use that to monitor the coin prices for the project you want to invest or trade on; Experience also helps, so continue to trade, learn lessons and become better
And also, before you sell a coin or close a trade; choose the same method; sell in batches; as it moons; the first batch would be your capital and little profit; the second batch would be more profits; never close your trades at once; and also remember, never enter a trade at once.
Selling is depends on the market movement. If there is a sudden pump then I think need to sell in hurry because sometimes after pumps it also suddenly dump. As long as you have it then sell and buy again in deep. Also it is better to divided your tokens to sell or buy so that there is always a back up. Don't sell in one go.