Answer
The average sizing for when drawing a fashion model is to make it 6-8 heads long. this means that if the head you draw is 4cm, there should b another 5-7 of them til the feet.
draw the head first and rufly make out with small dashes the length your drawing will be, and thn work around that. for things like high waisted trousers you might want to put the waist higher up to emphasise it...or for a long dress the torso length myt change!
one of thes is helpful to use while drawing...you can try to copy to the shape and move it to differnet poses...try checking out your local craft store:
http://www.misterart.com/store/view/001/group_id/1162/economy-brand-bloke
ikin.htm
