I don't have much in the channeling / mediumship skill area so can not offer too much by way of an answer. But I have gotten past-life flashbacks. They emotionally and sometimes intellectually impact this current life.
I've remembered being a reptilian, lizard, gecko-like creature. My job was to protect the eggs (Server?). I remember walking past the pit, where they safely lay, to the edge of a cliff. It was night. A clear sky allowed the stars to be seen in all their beauty. I walked over and joined my Essence Twin, a being of Priestly persuation. Together we looked up at the stars. We contemplated and sought to reach out to those beings who were there, there on planets, orbiting some of those stars.
Another flashback is an Astral one. I remember feeling expansionary, exploratory, curious for the new and thus choosing this Sage role in human form.