It's the uv layout. You cant just make another texture for a different model fit. Each unwrapped 3d model will have a different uv layout. You can save a uv template for the clothing in vam in the clothing materials/textures tab at the top. That will give you an outline of the uv map to see how it is set up, but you would need to modify/repaint the new texture to fit that uvmap.
What texture are you trying to put on what clothing item? I don't mind taking a look for you.