Never investigate alone; evidence gathered can be substantiated better or can be less likely dismissed with multiple members on site.
Be polite! Respect anyone or anything, when collecting data. Ask permission prior to conducting investigation.
When first attempting to contact by means of EVP, keep recording at roughly the same time each day.
If having trouble with EVP, try creating background noise (water faucet running, static on TV, etc…). The theory is that spirits are energy, and background or white noise gives them more of an energy field to manifest in.
Equipment should be up to date and checked prior to an investigation.
EVP Samplings of all team members are to be taken prior to conducting investigations.
Try not to whisper while audio recorders are running, it may be hard to differentiate between your whisper and possible EVPs.
No EVP recordings are to be done outside in a public arena, as there are too many variables.
Try to remain in a positive state of mind, it has been suggested that spirits may react more to positive people.