Using something as simple as post-it notes can be a great help when brain storming content ideas. It’s some we use internally and have Yes, No, Maybe/Refine groups.
To get this going, round up everyone from your content or creative departments and gather everyone around an empty table. Put up the post it notes on a wall near the table to represent your Yes, No, Maybe/Refine groups.
Then give each person in your group a stack of post it notes. Get someone's phone who has a stopwatch app. Set it for 1 minute, and tell everyone they have 1 minute to write as many ideas down (No matter how stupid) on the the post it notes and stick them on the table.
After the you have done this, as a group you go through each idea putting them into the category on the wall. Then do it again, set it for 1 minute and repeat a second time.
Doing this, and keeping the time short actually helps you come up with pretty good, simple ideas. As you don’t have time to over think it.