Take part in bounty. I believe this is the safest way to earn money.
yes, I agree, bounty campaign is one of the most secure programs, but this does not mean without risk, it's just the most minimal risk in my opinion.
I agree that signature bounty campaign is a good choice to earn cryptocurrency where you will only need to invest is your time and dedication to fulfill the post requirement. The higher the rank you have, the better payoff you get after the end of the ICO sale. You should also research for a good ICO that you wish to join in the signature campaign where you are assured of receiving your token share during the pay out.
There are many ways to earn money in Cryptocurrency, some with a signature reward campaign
as for Bounties which is ideally good if you are lucky to get a paid one. If you dare to provide capital there, you also have to be prepared against a number of risks.
Moreover, investing in ICO is one of the main ways, but it is very capital-intensive and requires a lot of work to be involved with you.