promo renders don't look good enough IMVHO.  try to set up scene, lite and matls so it renders beautiful.

use BB's anisotropic shaders for hair and eyes, snarly's EZskin (all posted here as freebies) if it's o.k. to use their freebies in commercial promos.

use SSS, BB's envsphere, HDRI, 1 inf lite w/ray-traced shadows, 4 RT bounces, IC=50, IDL=32, samples=6, SR=0.5, GC=2.2 et al.

do not use P4 render settings*.  do not render in empty scene* devoid of background, props et al.

you wouldn't get honest opinions, as rule here: if you can't say something nice, don't say anything. it's more supportive, but leaves users stuck in ruts*.