In the Cloth room click on the New Simulation button. Set the number of drape frames in the popup window. Then after you have selected and clothified the cloth click on the Collide Against button. In the next popup window you have the option to start draping from the zero pose.

This is one method of getting the clothes to fit but note that you'll only have the option to save the final result. If on the other hand you create a short animation you will have the ability to pick the best looking frame from a number. The natural motion of cloth will have some spring to it, a cloak will fall forward then slope back slightly, a skirt will swirl to the right then a little to the left. If you restrict yourself to just draping then these nuances may be lost.