Look to the team first of all and for the problem what they gonna decide. Lokk to the bounty manager who carry out but not all the time it's work. They need to have good website and good revious on popular platforms.
Also be aware of scams from other participants, recently I just discovered someone made a ''complaint'' using my name and profile link to change my ethereum address, thankfully I checked it and realized that it was changed. Everyone should always check their address because someone could just impersonate you and try to change it. In this case it was because the campaign allowed people to submit complaints via google forms.