Then what is the way so that I can make a big profit ...?
How to effectively avoid unnecessary losses ...?
Some of my most favorite trades happened when I wasn't paying attention (aka sleeping).
There might be something to buying a handful of the top market cap coins, setting sell targets at 200-300%, and turn off crypto for a couple months.
Worst case you're still holding the coins (at less value), but you at least don't lock in the losses (by selling at a loss).
I wouldn't recommend at the peak of a bull market, but we're far from that now.