Possibly the best way to convince someone that you are indeed a psychic is if you know a lot about that individual without them ever learning that you do. In short, by becoming a stalker you can become a true psychic. This works with individual marks and also in a larger audience. For instance, many psychics tend to go through a crowd and pick out marks before the actual show. They watch them, focus on them and try to catch things about them. Once they figure out something, they have sufficient time to prepare for the mark.
Successful psychics and mediums employ people to do this kind of stuff. These employees can either mingle with the audience and talk to find out stuff, they can even eavesdrop on other conversations and thus the information you collect then becomes useful in a large setting.
Does this sound a little intrusive to you? Well, there are several myth busting videos on YouTube alone that should provide you with enough proof of what we have to say. If you plan on giving psychic demonstrations then first find a subject and size him or her up with your skills of observation, stalking and eavesdropping. You can even get their name and check social media accounts to get a lot more information. Truth is that good psychics know how to use Google, social media and their senses better than you and me. In short they are excellent stalkers!