I've been thinking about composition a lot this year. Here are a few of my favorite books on the subject:
Mastering Composition by Ian Roberts
Roberts covers basic compositional information such as working with an underlying armature and thinking of big shapes. One really useful addition is a DVD that comes with the book in which Roberts takes his own paintings and changes them in a variety of ways to show how even the subtlest change can cause your eye to get stuck in one area of the painting and lose your central focus.
Creative Composition and Design by Pat Dews
This book is a nice relief from all the composition books that focus solely on painting. Dews includes a lot of her own collage work which translates to textiles very nicely. She also includes a variety of artists and their differing approaches to composition, some starting with shape and placement others with value or color.
Compositional Exercises for the Painter by Lucia A. Salemme
I like this especially because she includes many great master paintings and discusses what makes them work compositionally. She then gives suggestions for exercises based on the lessons of the masters.
I've been wrestling with the subject of composition in my own work. Most courses have you start with composition as step one, doing thumbnails of what your finished piece will be like, but I find that approach stifling. On the other hand, if I don't think about composition, I often end up with pieces I'm not fully satisfied with.
In painting, I've found my favorite process is to start painting loosely and spontaneously and allow the composition to develop along the way. Then I spend the later part of the process strengthening that composition. You can follow my process here.
But I can't quite figure out how to work that way in fiber. I like the spontaneity of gathering bits and stitching without a plan, but fabric is not as fluid as paint, and unless I want to rip out a lot of early work, it's hard to adjust a composition late in the game. One of my challenges for the year is to create fiber pieces with strong compositions that don't lose that spontaneous feel and process.