While I do most of my toy sculpting work in ZBrush, the essential toy designing tool after that it's Marvelous Designer.
Here is a thing some of you might know I don't sculpt clothing for the designer toys that I sculpt, I tailor them for each character, when I sculpted Mike Fudge's KUB I sculpted his body first, and then I tailored to fit the bear jeans and the hoodie, this is why it fits him perfectly and flows so nicely. It has weight, cause in clothing the two crucial rules are fit and flow (weight).
Each piece of fabric I create from scratch as a sewing pattern; then each piece is stitched and cut and tailored to the body to make it fit perfect.
And then once I created all the clothing for the toy, I export all the clothing in ZBrush for cleanup. Next stage is detailing and making them ready for production, cause depending on the piece sometimes adding too many details might ruin a toy, if you are going for a clean look you can't go crazy with folds and stitching.
No matter what type of outfit you want to create from a Detective Trench Coat to a Duffle/Gym bag or the leather outfit of Edward Scissor Hands or the oversized trench coat for Hellbaby Marvelous Designer is the perfect tool for that.