For those looking to organize everyone they follow into streams or lists, here’s a way to see the people you still have yet to list using Formulists’ “custom-list”:

Step 1: Add a “custom-list” on Formulists

Step 2: Start with your “Following” (or ‘followers’, whichever group of people you want to organize into lists)

Step 3: Subtract out any people you have already listed by ‘removing’ people that are in one, some or all of your existing lists (as shown above)