The 3 stage vigil is :-
Firstly set up your voice recorder, cameras etc.
Stage 1: 10 minutes talking amongst yourselves
Stage 2: 10 Minutes EVP session
Stage 3: 10 minutes silence & observing.
Have you ever tried this on an investigation and if so have you got any results ?
The theory here is the talking stirs up the energy, then calling out to see if you get any responses, then observing to see if any sounds or visual evidence.
If you haven't tried it, give it a go & let us know what results you get.