easy. create a burner wallet. add some eth to it but not too much. then participate in new protocols that arise. trade on them. add liquidity. mint an nft. i've recieved many airdrops just by being curious and seeing what new things are. if you have a burner wallet then if it is a scam you won't be scammed out of your main wallet. it is also good to revoke any permissions regularly if you are concerned.
zksync network is a good one to go and trade on. they have confirmed an airdrop will happen at some point. so if you want some free money that'd be a good place to start.
