Don't hesitate to sell out when it already reaches your target goals, the coins always have a sway and if you sell it out you can always go back and do the same thing, better to gain experience and explore every aspect of profitable strategy, combining short and long term is also good for experience traders, as they are not against the time each time they've trade.
However if prices start to rise and keep going up, we usually start getting greedy and start losing control for wanting to get more. Although the price of our goal has been achieved, we do not stop there and sell it right then and there. We still hope it will continue to rise. This case of problem is usually faced by a beginner, even people who are not beginners can sometimes get stuck feeling greedy.