Select the clothes or hair after loading (the root of the item, with its name, if you are selecting in the Scene palette or double-click in the viewport) and then use the Fit button in the Parameters palette, or right-click(Win)/control-click(Mac) on part of the item in the viewport and select Fit to... from the context menu. Pick the figure that should be conformed to from the list, click Accept if you used the right-click method.