>>3966634A. Find a photographer that reviews them, and does not obsess over test charts.
B. Look at lens specifications. Things to look for are number of aperture blades, it effects bokeh quality. And number of lens elements, it effects contrast of the lens.
C. Look at samples. It's possible to develop an eye for it.
Good example:
>https://alikgriffin.com/meike-35mm-f1-4-review-sample-photos/