What does hierarchy give you?
A focal point?
Two squares of the same size and shape have no hierarchy.
No contrast.
Equals no focal point.
By adding a different shape, you give the viewer a focal point.
The added triangle creates emphasis and a focal point.
Make one element different from the other.
And there's something to lead the human eye.
Add patterns to shapes.
Shape and pattern work well together, much like complementary colors do.
A pattern tells a story.
A smooth pattern seems modern, clean, and strong.
A rough pattern might get seen as earthy, imperfect, and human.
Create contrast in your work from different sources of texture.