If you are an investigator or part of a team, I hope you are using the enticement technique. This technique has the investigator setting a "scene" or putting out objects that would be familiar to the ghost you are trying to get to communicate with you.
Here's an example, people who are killed by being shot in the stomach area always beg for water as they die. Next to men begging for their mommas or wives, water is the most common cry heard coming from a battlefield. So, if you are investigating a haunting at a battlefield or field hospital, you could put out a pitcher of water. (For some reason, we get the best results from clear glass pitchers.) Then set up your cameras and recorders and ask if anyone would like some cold water. We have caught an old soldier saying "Yes".
We have also set up a poker table with old looking cards and chips. We have also used glasses of whiskey. Mark Nesbitt of Ghosts of Gettysburg has used a method where he finds a list of soldiers from a certain division and calls out for them to line up for payroll. He gets a lot of results from this method on Civil War battlefields.
To properly use enticements, you don't have to wear costumes, but some researchers do. You do just have to use common sense. Figure out who you want to speak with and try to think up something that would be familiar to them. Set out recorders and relax. The most important thing in any investigation is to try out new methods. Being too stuck in a system could hinder your investigations.
Hope this helps.