Direct opinion bounty, airdrops, and now you can work in telegram mining. Actually currently not much money is available from bounty or airdrops but you can earn some of money. But many new projects are managing airdrop so you can participate there if you want. There are some good channels where airdrop links of real projects are shared so you can easily collect them from youtube. A few years ago, a lot of money could be made from crypto for free. But if the number of such people increases so that's why the reward is to less.