An easy way to create a "Waiting for" area is under People.  When you add a person, do not add an email address.  Email address is optional.  Without one, this person is essentially your custom focus area or folder to store any task you want.  

  1. Go to the People tab
  2. Click on Add/Edit People button
  3. Click on + Add Person
  4. Add a name for your custom focus area or folder.  Do not add an email address.

That's it!  This has come in very handy.  For example, I added a person called "Dad".  Whenever my beloved tech-averse dad comes to visit, I would print this handy task list and give it to him.  I also help him with the tasks too.

SPECIAL NOTE: A paid subscription to a Personal or Team plan is required to add people.  

Related: How do I assign tasks to other People