People tend to lie and take advantage of others. People also tend to be gullible and expect the solution to their problems to fall out of the sky. For psychic fraud to occur both kinds of people have to be present.
It is generally difficult for a regular person to determine if a psychic is truly psychic or just a fraud. Personal integrity and thoughtful discernment go a long way in avoiding psychic fraud.
Rather than evaluating their psychic abilities, evaluate their personality. If you wouldn't normally associate with such a person, don't do it now either. Trust or distrust the person, not the psychic abilities.
If you still can't decide whether it's psychic fraud or not after you have been given psychic advice - then it doesn't really matter. Consider the advice to stand on its own.
Regardless whether the psychic is a fraud or not, consider the advice given with careful discernment and use the advice to help you come up with your own answer. This way, any advice is good advice because you have learned from it.