Based on my experience following the bounty, I will consider the following:
1. Bounty Manager (choose green trust or neutral trust manager). You can see manager reputation along with the projects they once held here: https://docs.google.com/spreadsheets/d/1B4sMp4rDeYjPn3Lkbxn6Ot5KLQFERPXloIl5lUbTVBg/edit#gid=662078362
2. Team (the teams who are involved are trusted and experts in their field)
3. Whitepaper
3. See the ICO Rank (higher is better)
4. See the project in what field (can the project be used in the wider community)
And for bounty campaign, you can join both of them or more like youtube, article, reddict, telegram, translate, etc. As long as you are able and to master every part of the campaign.