Airdrops are very good earners  but most of them turn out to be scams. or the value of their rewards very minimal. if you get good ones though, you can benefit a lot from them, Trading however is the more proven way of earning, if you are to take part however, you have to have a good grasp of the market trends to make good decisions on which coin to buy, which one to sell and when. Bounties are also good, but they take a long period of time to pay and some might turn out to be scams too