One of the things I need when I start a new project or when I work on a new feature, is the time of seeing ideas settling down.
Good ideas are goods after 2-3 days too. After a brainstorming is better to let the board rest a couple of days. Then you and your team will return back to it with a fresh mind and select the best ideas.
And then, again, you let the selection settle down.
It is not always possible, but I noticed that it is way better let ideas settle down. Sometimes you improve them. Some other time you see you enthusiasm as a team go down and reality force (similar to gravity force) do its job.