Joining bounty campaigns is the way to go. It doesn't require any money to invest, only your unwilling time and effort to reply to threads and reach a certain number of replies per week to satisfy the bounty manager. They pay you in whole when the campaign is finally over.
unfortunately now the bounty campaign isn't that good lately. many scams and cuts in allocations for bounties. a team that does not act sportively. same as choosing ico for our investment we must be able to choose a bounty campaign that really pays. because now I don't think anything is really free.