Whenever you are trading, you should have a specific target as to when you want to sell your tokens. Without a target, you will sell your coin at any price. But the target will guide you when to sell or either Hold.
Setting target is great, but Trading with target still depends on the project and its volume. Sometimes when you set a target, you may still have to be flexible with it because not all target will be met, that is why I said it also depends on the coin. Imagine someone trading a coin that is 0.0001 and setting his target to be 1usd, he may never get that target till eternity, and that would not mean the coins is not performing well.
If he has a flexible target and the coin increases to like 0.02, that is more than enough to have given him profit to move on with his life and to next project, except it is a project like bitcoin that one can really be sure of his future, then we can be rigid about our target. Personally I dont set target, once I see an increase, and I feel its ok, I move on to the next one, I dont have to be greedy.