I use to trade in short term. I choose a coin which have regular predictable waves (+-20-30%) and set buy and sell orders on the bottom and top of these waves. And it most cases it works for me. I also tried the strategy that you described but it's applicable only for a long term trading.
I do both short and long, and I do trend following for the long ones. I also do some little bit of selling pattern like the OP with some profit target in margins unless I see the coin or token is just going directly to kick the moon out of the way. The same way we have panic selling at the bottom is the same way I normally have panic selling at the top and it has always helped me.
When the value is just too good to be real, I sell it all out. You cannot always have it 100% but you can make a good gain and buy in back at a better value when the time is ripe.