We know that four way to cryptocurrency income such as Invest ico, mining, trading and Airdrop-bounty. If you wish, you can do any of that.
If you want to mining or invest in ico and need a lot of money, it has cost-effective risks and have also profits. And if you want to do trading then you can start trading only if you have some money. Here's a little less risk and have also profit.
If you do not want to take a risk then you can start the bounty. There is no risk here only you will have to work on time and you will get your payment at the end of the job. As a payment, you can get cryptocurrency and convert them into meaning by selling them. So, I think Bounty and airdrop is very good for earning risk-free cryptocurrency profit.
There is nothing like risk free in the crypto space. The only thing you can get to see is the risk reducing based on some certain investments or actions over the other.
Even bounty is not risk free because one way or the other, if you are not able to manage the risks well by doing some due diligence just as most investors will do before investing in ICOs, then, you may just eventually see yourself, getting to waste your own time on some shit coins and then either not getting anything from it, or you get to be bag holding such shitcoin forever. One thing you have to understand though is that, the less the risk, except you are somehow smart with it, the less you probably get from it.