In a group, we generated ideas of what the concepts related to dreams could be. The ideas that drew my attention the most were the themes of nightmares, warped perception of reality and surrealism.
Ideas I gained from this were mainly around nightmares focusing on common fears like heights, being chased, being trapped, falling etc. As for happier and more positive dreams I was thinking of mainly fantastical, childlike things like Disney princesses or other fictional cartoons.