[Orgmode] Where ends a subtree?

[Franz Heuser]

Hi,

I wonder where an subtree ends. My work flow is as follow:
* headline
  some text... 

Know I notice a ToDo entry that is link to the text. So i type

** ToDo something useful
   notes about the ToDo

  ... more about the headline.
  
My problem is, that '... more about the headline' is hidden, when the
ToDo entry is folded. It belongs syntactically to ToDo, but semantically
to the headline. 

Is there an <end> Tag or something like that? Where i can say: Here Ends
the ToDo entry, what comes now belong to the last headline?

Any Idea? Or a hint, how i can use org-mode another, better way? 

Greetings