You can figure out if they are low quality or not pretty quickly if you are honest and vulnerable with them.
If they treat you bad or ignore you after you are honest about how you feel, then they aren’t for you. If they reciprocate and tell you they feel the same, then they are right for you at that time.
Never, ever waste your time on someone that doesn’t want to be with you. I think that alone solves a lot of problems because you can evaluate their character quickly.