Consider it a VC investment. First, you gave to either understand the underlying technology, or someone you trust have to understand it sufficiently to be able to say "this is bullshit", or "this is a great novel idea that makes a lot of sense".
Then you invest a bit of your really disposable income in it and don't touch it for a couple of years. Eventually you sell once you're happy with the price, or you forget about it and check few years later.
Edit: also, it really is down to luck too. An idea might be great, but the people behind it can be scammers. Etc. Crypto is(or was) a very high reward, very high risk game.
And for God's sake don't invest your life's savings in crypto!