Do the clothes have "morphs"? If they do, all you need to do is select the body part of the clothing and adjust the morph dials in the Parameter Dials. If the clothes do not have morphs, that's more difficulty because resizing doesn't usually work for fitting clothing. In cases like this, you can use "The Tailor" in order to add some or all of the figure's morphs so that you can fit the clothing around the pose. I think most of us now use Wardrobe Wizard (found at PhilC's site), to fit clothing from one figure to another, or from a figure to it's morphed up one. Working with some poses where legs stick out, or the figure is sitting etc, is a real challenge regardless of what you use to fit the clothing.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi