It would be amazing to have all characters on an aligned specs and dress them seamlessly, this is all I would dream of... but reality is a little more complicated, after all I do several tricks to make clothes look nice on them and invest a lot of work on trying to make them unique in their own way.
The picture above is one of the many folders where I save presets and references for the most rich part of the design, the body: with partial dials and group dials you shape them and their history, it's not just about visuals and sizes.
The shapes are built differently and there are different ways to achieve similar shapes, and sometimes things just don't work properly depending on which morph you're relying on - not even considering custom deformers that I use for special cases like Debra, Vanessa, Eden and others.
But I won't lie, some characters share shapes and skin: Monque's and Melissa's skin base skins were used to give life to more than one character, each of them became its own variety of skin tone and different details, others are a mix of 2 or more skins, after all some textures look bad and need a little tweak - old trick used on some magazines but, that's a talk for other day.
As for the shapes, back in the day I used some base pre made but after the problems fitting it to the bodies I use very few base body shapes and continue on base parts ones, like hip and waist size, thighs thickness and their variations until I get the perfect shape - but I can use a base character to create a new one.
A good example is Jana: since her mother and sister should look a little like her I toned down her base model and reshaped her to the bottom heavy Mandy and her voluptuous mama-mia Mother . The same, but different, like it happens in real life :P
Just writing this after rewiring some shapes on a base model so it would fit clothes better... and it didn't work and I had to edit the clothes - that's my work after all.
The configs above are for characters where I usually struggle making clothes fit, there are some old names there too, haha.