Let me rephrase my question again for better understanding: Which signals, what techniques, which movement do you consider while making selling decisions so that you always make best possible profit in the given scenario? If I chose right time to sell my futures, I would have made 10 times more profit.
Recently, I've spread myself to investment outside of crypto, into stock and shares and bonds even. It seems to me that one important factor is how long you intent to keep your money in there for. As such if its long term then I just don't bother much as its long terms so any short term losses are ignored.
As for short term, which is the case with crypto and what you're describing I do not have a magic formula but I sell out when it all looks like it will crush. At this point I'll be happy to cut my losses and take the profit I can. Obviously I'm tempted at times but I find that with a little flexibility I can do just fine. This of course requires close attention to trends and it's not 100% but I can make terms with it.