On my own opinion, first check the white paper of the project read and see if theres a unique idea and if not and the same from the other project you pass by. Another is check their website if properly arrange and well design. Then if you are convince on the project that it has a big potential see now the bounty manger if its legit and no red trust. Managers rank is not important sometimes because the own company appoint their own bounty manager and sometimed its newbie and legit. Dont join too much bounty just learn to choose quality over quantity.