You can do these tips, I always do these first before join bounty campaign.
1. You have to see their website
You must check all about the project on the website, such as: What project looks like, Roadmap, Whitepaper, Features, Team, and Social Media.
2. Bounty Manager
Of course bounty manager is the most important on bounty campaign, famous BM will give you a good service and almost all the projects they handle are legit. You can follow/join their program from Bounty Detective, Wapinter, Btcltcdigger, or Arteezy.
3. Hope
We only need to hope, we don't know how the project will develop in the future, even the project that is listed on the exchange can be exit scam.