Today it is nearly impossible to choose. If you really could find the perfect project it can be endinng bad too. I believe that %5 project could pay you these days, no more. If you still search for the good project you need to use some bounty platforms, on bitcointalk it is risky i believe. Try Bounty0x, i think this is the best bounty platform right now.  https://beta.bounty0x.io