Mama used to say: "Ya gotta test the fruit, baby. That's what Jesus said. If you wanna know about people's roots, be sure to test their fruits."
People aren't as complicated as we think they are. If you're paying close enough attention, people will show you who they are. Remember what auntie Maya Angelou told us: "When somebody shows you who they are believe them the first time." Auntie knew. That's why she said that.
So if people show you who they are, then you've got ALL the information you need to decide whether or not you should be taking advice from them. In case you don't understand here's an exercise to take before deciding whether or not you need to listen to certain people's advice. First, think of the person you are considering taking advice from and answer these questions:
Does this person have any experience with what you're struggling with?
Do they have any experience overcoming the issue that you are facing?
Have you taken advice from this person in the past and if so, was it helpful or harmful?
Does this person appear to like the choices they make? Have you ever caught them saying: "I am so glad I chose to do XYZ!"
Look at this person's life overall. Would you say they have a positive attitude or a negative attitude?
The answer to these questions will help you determine whom you should take advice from. You never want to take advice from someone who has terrible results in their own life or who doesn't have experience achieving what you are trying to achieve. Be picky about who you consult with about your life.