I have been making clothes with MakeClothes for quite some time now, and I have read all the documentation available, plus many forum posts here and elsewhere.
But I have yet to discover the mysterious method for making an article of clothing fit a wide range of body shapes, especially older humans.
I have done it accidentally a few times, but more often than not the clothes I make fit well to whichever form -- male, female, base, child, baby -- was used to make the clothes, but get distorted if the human is modified too far beyond that form.
The distortions always appear in places where vertices are close together, such as the armpits and crotch areas, but necklines, waistbands, and sleeves can also get warped (mostly with humans in the senior citizen age range).
In some cases, changing the human even slightly makes the clothes get all bumpy, like a Shrinkwrap modifier was applied with a large offset but no weight paining.
At first, I thought it was just a matter of polys, with low poly meshes fitting better than medium to high poly meshes, but although that does seem to be a general rule, it does not apply in all cases.
I realize that some parts of the human are gonna slightly stick out through the clothes (breasts and buttocks mostly), and that's what the Mask modifier is for, but masking doesn't cover distortions.
I have studied several of the user contributed assets from here, and some of them fit more humans than others, too.
It's not too much trouble to use Blender's proportional editing to fit an article of clothing originally designed for one gender/body type to another, and then just run MakeClothes again using the appropriate human form, but I don't want to do that unless there's no other way to go.
I created male and female senior and plus-size human forms using that synch mesh thingie (pretty cool feature, BTW), ran MakeClothes using those forms and the clothes fit those forms but only tolerate slight changes to the human before they get all distorted.
Now, it's one thing to have male and female versions of an outfit, but to have male, female, senior male, and senior female -- as well as plus-sized versions of each for a total of eight -- is a bit much.
I have tried lots of stuff like:
using humans with helpers
using humans without helpers
doing that "controlling the results with vertex groups" thing
creating vertex groups automatically (usually works better for me than the above method, BTW)
moving/relaxing vertices to be farther apart/straighter in armpits and crotches
adding edge loops for more flexibility
dissolving edge loops to reduce density
subdividing
un-subdividing
...all with mixed results.
So, is there a trick to it, or is this just the limitations of the software I'm running into here?