For these two, they each had a removable vest, and Man #1 also had a jacket. This made these two the most difficult, since the pieces had to be patterend so that they would actually fit like normal clothes while anything else could just be sewn in place. That's why I actually started with these two first when I was making them.
In addition to the vest and coat, Background Man #1 also has two different tie options.
To give the illusion of properly layered clothes, they have little strips of felt inside acting as legs so that the pant legs can cover where they sew onto the shoes. Man #1 also got socks.
The legs are simply tucked underneath the torso part of the "pants" and sewn.
The women also have interchangeable fahion pieces, but they're much simpler than the men's. They each got an additional skirt piece.
Here is Background Woman #1 with her additional skirt.
Background WOman #2's first option, a simple sash with a bow in the back.
And her second option: a grey wool overskirt and scarf. The two are sewn together since the ends of the scarf tend to refuse to stay in place otherwise, but the whole thing can still be removed easily over the head.