I just got your message on Tumblr, for some reason I didnt gett an email notification... Anyway, It would be my pleasure to share some ideas I've had for gentle trans giantesses and tiny guys who love them.
I've found that the simplest and often easiest way to fantasize about such things is by starting a story off in a multiverse, or where a regular person gets some how transported to another world or reality, in which they are tiny compared to a gentle, loving trans woman.
Other ideas include the classic shrinking or growing scenario, stories where magic or science is involved, etc.
If you have any ideas you'd specifically like to flesh out, let me know I might be able to help. I'm not an author, by any means, I just like romance in general.