It doesn’t work for everyone, but I’ve found that talking a fantasy out loud during sex can enable everyone to stay connected & present while exploring (sometimes outrageous) fantasies. The physical sensations can, to one degree or another, reinforce the fantasy. It can either be one person doing the talking or both co-creating, depending on how it works for the people concerned.
Of course this assumes (i) a knowledge of the preferred fantasies & dynamics of the other person, (ii) a good storytelling style, (iii) no strong ego attachment to any one type of tale, and (iv) no adverse judgments regardless of what kind of fantasy, ever
For myself, I love to be verbal and conjure up new worlds and possibilities, and I’ve had a few partners who’ve really enjoyed this. One in particular loved exploring her sexuality through fantasy (she’d tell me at various times what turned her on, and I’d then use this info during sex) and we’d fuck for an hour or 90 minutes at a time, meandering through multiple scenarios and she’d cum perhaps twenty or thirty times before being too blissed-out to continue. Some of the fantasies we turned into reality; others were clearly just for the imagination. All were powerful and mutually satisfying. And we were both always 100% present, locked into a beautiful dance of mutual mental stimulation and discovery.