I think the best way to earn airdrop is to have a lot of btc. For example, if you had 20 btc when it was cheap, then from then on every fork of btc you got 20 coins!

so imagine, right now u have 20 BCH, 20 Bitcoin Gold, 20 bitcoin diamond and etc. It's just a money multiplier over and over.

I think now you have to find the coin that looks promising and is cheap... like Ethereum. Ethereum is becoming like bitcoin, so just grab and hodl like 20 Eth and wait for it to fork a lot. Then you get 20 of their coins too!