I've experimented with spawning people in the last few days and I've made some progress.
Unfortunately the 'imagine the person behind you' trick never really worked for me. Now I just try to shout their name while walking around and expect them to come to me. Last night I asked a DC how to spawn a particular person and he told me that it's difficult and I should go to IKEA. So I went to IKEA and found the person I wanted to spawn there. Unfortunately she turned into a strawberry.
Does anyone know a better way or a trick to keep the person 'stable'?