Being patient has always been a good one, buy low and sell high is always good, be greedy when others are fearful and be fearful when others are greedy works as well. These are literally sayings and not even indicators or tips in technical sense and they all come out of the same result.

If you know that one thing will be good in the future and not have any fundamental issue, you should always wait for it to crash for a very low price because of something and just buy it during that period, and wait for something huge to happen to make it increase. Bitcoin is like that, but do not think the same for some small bad shady token, only few coins are that much trustworthy.

Buy them when to go 50%+ down and sell them when to go 100%+ higher and you would make money without a doubt, and it always does those falls and ups.