What is the best way to invest in cryptocurrency?
That totally depends on the nature of cryptocurrency, if you are talking about BTC then investing by keeping the knowledge of halving, phases, cycles, etc. is important because 4-year cycle is what that can make you sure money (as you have taken some insurance but you don't in reality) if you are talking about other alts then that also depends on the nature of alt too. Because there are different types of tokens with different narratives, some are the best of its category.
Some are to hold, some are to trade, and some are to just take benefit of and never look again on them, there are a different ways of making investments in cryptocurrency, besides trading and investing (holding), we can participate in Farming, staking, LPs, etc. but that's are not an easy task that if we think we can make easy money by locking our funds into any of these and can make profit then we are wrong, proper analysis and strategy is also needed here.