I would love to see more tunic type glams similar to the Eikon Acton model. There are very few items like this in the game. I like pieces that drape down a bit below the waist and above the knee. Bits of armor on a robe is cool too, which unfortunately we don't seem to get very often either. The bit of concept art below is one of my favorite looking pieces of caster gear I've seen. It looks masculine to me and functional.
Healers especially suffer with glam pieces that really seem tailored more to females. It feels like the majority of healer chestpieces are full robes with a wide or bottom-heavy silhouettes. I like robes. I like men in robes. FF mostly doesn't do men in robes well imo. A robe on a man should ideally accentuate the shoulders and chest and then taper down to something straight. This would be an example of a more masculine full robe to me.