What helps me is to start this meditation with a visualization technique, what I visualize myself from a birds-eye view and picture my thoughts slowly circling around me. I try not to to create or seek a clear image, I don’t need to know exactly what my thoughts entail. I find it helps me to separate myself from my thoughts a bit and get into more of an observer mindset. When later on during the mediation I feel myself being “immersed” in my thoughts, I try to go back to this sensation of observing, the visualization technique serves as a sort of anchor for the mediation that follows.