There are so many way and guides on how to choose bounty campaigns but in my own experiences, I only do two best known way to choose better bounty campaigns.
1) participate on bounty campaigns that are being managed by good bounty campaign managers like Yahoo, Sylon, Needmoney, Arteezy and other veteran bounty managers in the forum.
2) Check their social communities like Telegram Channels, stay away from ICOs and projects that has no telegram channel or very few members or no active members because they are scam and will soon fail.