Aside from typical bounty campaign and airdrop. Now the hype change to incentivized testnets. There are some projects who are testing out their platform and able to give some free token during launch. Actually this isnt new anymore as it being done in the past. Gonna share some of the projects Ive done on testing. Dont have tokens and the task are not too hard but some are long process.
DISCLAIMER:Not affiliated on any of these projects. Just sharing here in case you are looking for a reward task like bounty and airdrop. Im not confident too if there possible scam to that but I checked their social and details and looks good. But of course its always better to be cautious so like I said only used new wallets or dummy email accounts or any important things not to connect with for these kind of tasks rewards thing.
It's worth giving this a try as a bounty campaign and airdrop is not worth it anymore, I read a lot about test net before from my friends on social media but ignored it I have another computer and will want to give it a try I'm sure there are still a lot of testnet projects coming up, this is really not something new I first come across this test net for free tokens early last year, and I agree with OP be sure to only use disposable wallets not your main wallet, just to protect your funds as you are integrating the wallet to these projects.