Hey, thank you very much for the kind words. I'm so happy to hear that. 💖 I don't use social media for "White Russian." But there's a discord server. Link
There you could also send me fan art (via DM or in the public art-channel). I'm looking forward to it. 😺
I don't know about advices, but I can tell you how I proceed. Others work differently and that's cool too. 👍
I wouldn't create too many main girls if it's going to be a Harem VN. Rather concentrate on a few and develop detailed characters. It also depends on whether you want to tell a story that follows a major plotline (like a movie or series), or whether you want to jump from one (kinky) scene/or date to the next without an overall plot.
Think about a setting first. I wanted to tell a anime-like story that revolves around a cafe that eventually starts selling breast milk and whose maids keep getting bigger boobs.
Then, naturally, questions arose as to why the girls were lactating, what is their relationship with the MC (friend, boss, relative, classmate). Then think about classic stereotypical archetypes that you like and want to have in the game. (sporty girl, shy girl, nerdy girl, arrogant girl, popular girl, etc.) To make sure they don't stay in the stereotype and it gets boring, give the girls additional characteristics. Maybe the sporty girl is also insecure with her body, or the shy girl is good at a certain hobby that gives her confidence. Maybe the arrogant girl is very reliable and helpful when it counts. Or present the girls as stereotypical but gradually show that they are actually the opposite. Maybe the cute girl is actually slutty and loves to show off her body. when she is around the MC. Something along these lines helps to make characters entertaining.
Also think about a reason why the girls are growing. And then how the girls react. Do some like it, do some want to stop it. Once you've built the framework, it actually works by itself, because you only ever have to ask yourself: What would be the next logical step?
If you find yourself at a dead end and don't know what to do next to continue the plot, it always helps to bring in support characters who have contact with one of the main characters. (The parents of the girls/siblings/friends). In the relationship with those you can show more facets of the main cast and deepen their character. Support characters don't need that much depth. Their main task is to make the main characters shine. Another possibility is to change the setting/location. Then you can work with the environment. Are they in a shopping center/cinema/park/beach? What can you do there and what situation do you want to put the characters in?
It's already quite long, so I'll stop now. I hope I was able to inspire you with a few ideas. 😺