Technical analysis is not to exactly predict the price in the future but only to give you idea on what might be the price in the future, because it could go sideways (that's why setting a stop loss and take profit) is very important.
So your question is on what price you'll set to take profit? The answer to that is depends on what price you are satisfied to take profits based on the technical analysis you have on a certain coin price chart movements. Because just like what I've said, technical analysis is not 100% accurate.
Always take profits when you're happy. A profit is still a profit, while your regret is not a profit at all.
Price can go sideways because of different reasons and to know these reasons it's important to stay updated either by watching the news or by visiting the forum because people also talk here about the latest happening in cryptocurrencies which can affect their price. There's actually a term for that or when you scout information outside, I think it was called fundamental analysis.
It's beneficial if you can include that on one of your trading/investing strategies. Taking an action immediately can also secure the predictions that you just committed because there is no way that it will be reverted once you already sold or bought your coins.
one way to keep tabs if you are holding specific coins is to subscribe the social media channels of a given coin. because most of the time, there are discussions that are not being discussed on ANN threads or their blogs or their site. as it is now easy to post small updates via soc media channels like telegram or twitter, some of these devs will post something on these channels. now, if you feel they are being silent and hard to communicate with. maybe, start thinking of getting out while you are still in positive profit. because if they are not showing activity or any enthusiasm to their community, something is wrong with it. you need to get ahead of things, otherwise, they will possibly leave their holders hanging.