I don't, and have never contacted any, they seem to show themselves to me for some reason. I just don't know what to do once they have made contact.
I suppose it would depend on what outcome you want. For myself, if/when I have an encounter, whether it be nightmares or physical encounters, I try to figure out what has brought them to, because there is generally a reason. Maybe something I've been given, or bought secondhand etc. Then I get rid of that item, or whatever it is, because it is being used as an invitation for these demons to come to me, and I don't want it.

Of course, if you want to be contacted, you'd probably be better off speaking to Maz or Punks