Thats difficult to do well.

I support the "do really inhuman ones" and "try created psecies".

A very good example from my pov is the
Spoiler: Perry Rhodan up to around silver book 40
Show
Haluteans/the Beasts from the Perry Rhodan Universe.

Result of a galaxywide eugenics/Radiaten Experiment program to design the ideal soldiers.
With some steps in bewtween ended in beings that expressed behaviour humans interprete as male or female. And tough as they get to boot




Also no, avoid Asari, the only thing well done with them is the Scene with the bachelor party where humans, Turians and Salarians all say they look like them. ;)