Here I've cut away some of the Sculpey around the area of the left buttock. If need be I can always add more if too much was removed. The idea is to roughly suggest or block in the folds before refining. A little more Sculpey had to be added to the buttock to make it look similiar to the right one.
The fold after blending. The great thing about Sculpey is being able to take away or add more as needed without the worry of the material curing in a short amount of time.
A view of the back of the left leg that also shows the folds behind the knee. Note that I'm trying to be mindful of the leg's position which affects the folds on the trousers.
Take note of the angle of the left cuff. It hangs a bit differently than the one on the right. It also helps to accent the angle of the ankle and lower leg.
I try to move around the whole work area so equal attention can be given to the entire leg. Here the area of the crotch has been reworked a bit. I was not too happy with the folds and decided to play with them a bit.
The following photos show the remainder of the work that needed to be done on the left trouser leg. The rest of the work shows the folds cleaned up and refined. I did decide to rework the folds on the upper left front of the trousers.
In addition to the posed photos used for the pose, I also looked at several period images, especially those showing men just wearing shirts and trousers.