Well one thing I like to do when testing out a new AVN is something I like to call my 'Negative Reaction Test'.
It means I go through the whole AVN making every available choice in the most negative way I can. The point is to test out what changes the choices actually make on the story.
Do the characters say anything about the way the choice was handled? Does the AVN skip dialogues or is it exactly the same dialogue regardless of the choice made? (I see this disturbingly often. Characters saying that the MC had sex with a female character when in fact I had not allowed the lewd to take place...)
If I encounter a character I really like or some story element, then I will replay the whole thing making much more positive choices.