Another odd one, but I like to put a mirror in my line of sight -- not right in front of my face, but where I can look into it. It helps to give you a sight cue, and you can talk to yourself as if you were looking at the person on the other end of the line (this is assuming you are doing a voice-only call; not a conference call that is using a webcam.) Speaking of that, be prepared for the possibility that a videoconference requirement may be sprung at the last minute -- make sure your computer can handle it if they ask you.
If doing such an interview from home, I prefer having the kids taken somewhere else entirely. You don't want a loud crying jag or a huge thunk to be audible through the phone. (Sometimes sounds like that can penetrate a closed door. When my 13yo decides to jump down the last 4 steps upstairs, you can hear it for sure in the basement office.)