I have been wanting to improve my fashion illustrating ability for a long time. I keep a sketchbook full of my design ideas, but the illustrations are so amateurish. I heard from others that these two books were particularly helpful, providing fashion illustration tutorials. I just ordered them from Amazon today and should receive them by week's end. I'll post a review here after I've had a chance to peruse them.
And just so you can imagine the dire necessity...here is a sketch for a child's design from my notebook.