Hats and caps for embroidery

[GraSS]

Hi everybody! 
I've never made embroidery on hats and caps and I need your advise. 
Which hats/caps are better for embroidery? On which ones embroidery will look better?
I mean structured or unstructured? 5- or 6panels?

[Filling]

As for me structured ones seem to embroider better, because there is less movement.