cash out only when you already reach the target, trading really need a lot of patience
and also when you need the money, that was the excellent time to sell and cashout.
Enjoy your profit, most people didn't shop with their bitcoin so they've just satisfied with all their bitcoin on their wallet. to me, it will make me lazy to gain another profit on bitcoin when you see a big amount of bitcoin on the wallet
Cash out when necessary when it is for emergency reason or what, don't let your sensitive emotion decide for you, be smart enough to do wise thing, if you are still struggling on it, pray that you could have a right decision in anything that you are doing in your life especially here in cryptocurrency where in it can change our life.
The answer is personal every time because it depends on your needs and situation. There is no exact answer for an exit plan from bitcoin or other cryptocurrencies. The best, you will decide on your own when to exit and cash out.