So, I just learned about [Typeplate](http://typeplate.com/) (gorgeous, lovely, and will most likely be a staple in my toolbox…) and once again ran into something that I finally decided I needed to ask people about.
Now, to start this off, I am not a designer, I don’t have any education in typesetting, layout, etc, so my questions are born from curiosity and wanting to better myself rather than trying to claim anyone’s wrong, so I’m interested in the discussion more than anything else =)
You certainly don’t have to follow the rules to a tee, and there are many ways to create hierarchy and contrast. I think it is really project dependant, but I definitely recommend that you experiment and see what you come up with :)
A good test is to blur your eyes, if you can’t see the hierarchy, then it still needs work.