There are various ways to shape a shawl and I’ve been having fun experimenting with different styles of shaping. I currently have a design that I’ve sent to a publisher for a crescent shaped shawl. Crescents are interesting because there are so many ways that they can be shaped.
A triangular shawl with a fast rate of increase on the outside edges can be crescent shaped with a bit of a point. A crescent can also be made with short rows running side to side, like my Tierra Shawl, or with short rows running up and down the shawl. You can also increase and decrease knitting from one end to the other. Or you can make a part of a circular shawl. You can also space out the increases in a top down shawl to make a more crescent shape. I’m sure there are more. I chose to move from a initial set of short rows to form an initial crescent shape to spaced out increases to create lines of lace curving across the shawl.
Here are some of the better websites I’ve found that detail the basics of creating different shawl shapes:
This Tricksy Knitter post on shawl anatomy doesn’t give specific directions but it does give you an overview of how some basic shapes work. http://www.tricksyknitter.com/shawl-anatomy/
Likewise, you will get an overview of some additional shapes without any specifics at Tin Can Knits. https://blog.tincanknits.com/2012/06/12/shape-of-lace-part-one/
The Shawl Knitting Cheat Sheet gives you some basic information for five different shawl shapes. http://www.laylock.org/blog/2011/05/free-shawl-knitting-cheat-sheet/
Holly Chayes shares detailed directions for 15 different shawl shapes, often with directions for starting top down and bottom up. http://www.hollychayes.com/2013/04/15/shawl-geometry/
Julia Riede has basic directions for 23 different shawl shapes on her web page with a lovely visual guide to go along with them. http://www.jriede.com/shawl-shapes-overview/