Thrive's workflow is our usual system for how ideas go from creation to implementation. For anyone new to the project, this explains the roles of our different websites and how they fit together to form the development cycle of making the game.
Obviously different situations will need different workflows, but sticking to this system for as many tasks as possible should give the best results.
We create and discuss new ideas on the forum. This could be something dev related, like "We need to replace the nuclei with disco balls", or it could be something organization related, like "We need to update the wiki page on the Microbe Editor." Sometimes though, ideas are obvious (like bugfixes) in which case we can skip this step.
When we complete the discussion for a game feature or wiki change or something on the forums, we then create an issue on GitHub to track that task we want done. We can assign it to a person, give it tags to categorize it, assign it to a release version, link the forum discussion that spawned the idea, etc. Using the above example, we'd create an issue called "Replace nuclei with disco balls" or "Update wiki page on Microbe Editor".
Once an issue is complete, we create or update a wiki page for it if necessary. Using the above examples, in the first case we'd update the page on Organelles (or whichever page it is) and change all references of nucleus to disco ball. In the second case we wouldn't need to add or update a wiki page because the issue literally was to update a wiki page.
then fills in the gaps between all these steps by being a quick and easy communication platform for questions like "Hey can you give me access to our Twitter page?". And also serves as a place to casually discuss about new ideas before discussing them on the forums.