The cloth belt tag is fairly simple. To attach cloth arms to a body as I did in my sample project:
1) move the arm into position and add the cloth and belt tags to the arm
2) drag the body into the “Belt on” window of the tag’s attributes
3) put the body in X-ray mode (Attributes > Basic) so you can see the arm inside
4) select the points on the arm that are inside the body (which must be editable), and then click “Set.”
Alternatively, you could select the points on the arm and then move it into position, add the tags, etc. Just remember that you can’t move an object with a cloth tag on it as it is a dynamics tag. Also, make sure to give your cloth objects lots of subdivisions, either before making them editable, or by placing them in a subdivision surface after doing so.
Have fun.