I would like to kindly respond to your ideas.
I too, am actually a writer, and writing "Adult baby fictions" or "Age reversal fictions" actually isn't to easy. I have seen people do stories in 30 minuites, but my stories take about 8 months to a year and a half to completly finish. So I can suggest straight away for patience. It is important to remember that especially if this is a first time writing such a book. Furthermore, I suggest you spin up some cotton candy. Yes. cotton candy. I am not referring to the sugar however, but the classics. Take your own spin on the classics, as transforming to a child is not possible in this world, is there a way you can make it sound exciting while at the same time twirling it with the strands of fantasy? It's a little harder than it seems.
Lets use the example....um...lets say the "baby ray." This on it's own is used WAAAAAYYYY to much in fiction, and most people see it as predictable or dull, and few people really appreciate it in its full classic form anymore. But wait! What if you put your own turn on it? Mabey.... Lets say there is a new experiment? A house party? a scientist? Or mabey.....A friend of yours who is a scientist offers you to a house party and has found out your tendencies toward a younger side, and gives you a win-win. You test his experimentation gear, and you get to enjoy a day as said baby, but keeping your memories and things as a safety net for the experiment, so you can still do basic communication, and tell him how it is working out, or what isnt working out. Need a story expansion? Great! Turns out at the end of 24 hours he admits that he actually still needs to ...fix his change-back potion, ray, secret power ring whatever to change you back, much to your surprise.
There. A twist on a classic straight off the top of my fluffy puppy head.
Now if you want to take a FULL original twist that hasnt been done, expect very very very long tedious, careful research, design, planning, preparing, modeling, and testing. But hey, im just trying to make this easier.
I may not be the best at typing, as you can tell from my misspelling, but this is how I got 50 subscribers, and 2000 reads on my new book and on 253 digital bookshelves on another website.
I wish you the best, and I VERY much look forward to reading this story! <3
To further answer your question, I try to use my imagination a lot when in my little space. I usually enhance by playful and happy music. It's that feeling of wonder like your seeing something for the first time again that makes being a baby puppy so wonderful.