Usually i fully edit models to the point where at times it's hard to tell what the base is, spending 15-60 hours in blender and unity per model depending on what i want to do with it and often times having to create my own makeup textures because the innocent school girl look is just not for me in most cases.
I've edited at least 5 Manuka's, 10 Rindo's maybe 2 Kikyo's and same goes for Selestia and Moe. So far and i'm currently working on Sio.
I fully understand what you mean about Velle as my partner uses her as his main and is constantly readjusting clothes that are made for other models to fit her because there is bare minimal if anything at all with varying styles.
I always went with what i did based on the flow, what i mean is i would find inspiration from others avatar creations OR simply art work that i see on twitter or even youtube and brain storm ideas, then once i've got an idea on what i'm going to do i'll pick a base pretty much based on what sort of vibe i want to go for, body type, how long the eyelashes are, face shape etc. For instance if i wanted a chill small chested avatar i would most likely go for Manuka as she doesn't have a lot going on as GodFather said and i can make her look more tomboyish than other avatars whilst still having a cute charm due to her face.
It's really just personal opinion. If a model doesn't fit what i have planned then i will do a head swap, taking the head from one avatar and attaching it onto a body of another to better fit what i have planned for it. Hope this helped and sorry for it being so long!
