The team that you hunt with is one of your most useful tools on an investigation. They are the ones that gather the evidence and then interpret the results. The solid group is the way to accurate results. But how do you select a team? Odds are if they are willing to go on a ghost hunt in the first place then the group will be stacked with those that believe in the paranormal. The trick is to getting a group together that believe in many different things. I devised a questionnaire that I have everyone in the group take before they even go on a hunt with us. The reason is that I can obtain all the information about that person before they are exposed to anything else.
Questions range from personal beliefs in the paranormal to religion to how they would feel if something did happen on an investigation. The point to all of this is that I can figure out what would happen on an investigation. If someone is prone to imagining things then I can most likely assume that an owl hooting or the wind blowing could become a paranormal experience for the person. The results are then in question. But if paired with someone who does not believe in the those types of things and they describe the same thing and feel the same way I can then feel a little more comfortable about the results. It allows me to have a little more control on what I can believe from the evidence gathered.
Most importantly you need to have a group that you trust completely. It does no good to have a wise guy in the group who destroys the whole investigation by creating paranormal occurrences. Likewise, it is hard to complete an investigation if someone is easily prone to freaking out during the hunt. Know your group, trust your group, allow your group to get the results honestly and you will always have a successful hunt. Even if you do not find anything you will know that everything was done correctly and by the book.