Title says it all.
I think the biggest problem with this is lighting.i dont really know much about texturing but i know a few studio lighting setups if thats what youre going for.
there is this:
and this as a HDRI:
more examples here:https://www.google.co.uk/search?rlz=1C1CHBF_en-GBGB745GB745&biw=1920&bih=901&tbm=isch&sa=1&q=studio+lighting+setup+hdri&oq=studio+lighting+setup+hdri&gs_l=psy-ab.3...148215.153236.0.153490.12.9.3.0.0.0.241.709.8j0j1.9.0....0...1.1.64.psy-ab..0.6.211...0j0i8i30k1.w2R5VD6kuK8#imgrc=5a2Y9RrArRvLgM:
Adjusted textures (specifically glossiness and roughness), increased sampling a bit, and used an HDRI. Thank you, Yusuf Raja!
This could solve all your lighting problems: https://www.youtube.com/watch?v=QPaHGm-vrAc&t=1093s
Did I mention that I love Gleb Alexandrovs tutorials?
In many cases 1 HDRI is not enough!