I haven't given up on the idea of pinterest being a good way to study composition, but I don't think the link I used yesterday worked. I always send myself a copy of the blog for the day to be sure it's working and when I tried the link today, a window came up that said "oops, try again".
Today I will try linking to the page that shows all my boards. I put Composition in the top left corner. If this work maybe I'll try setting up boards for different types of composition, grouping by armature. For now, I 'll go with one board.
I found two more "S" compositions in my own paintings. One that might have happened by accident, but that I like is below. Notice how the pumpkins in the front are in the shape of an "S" and I think they do draw you towards the back. The radiating lines take you back, too. According to Ian Roberts, it is okay to have more than one armature and it can be most any shape as long as there is something holding the painting together, like the armature that holds a sculpture together.
I would appreciate your comments about whether this Pinterest idea is working. It's helping me organized my thoughts about composition.
Tomorrow I want to concentrate on the use of the diagonal in painting. I've been out gardening in this heat and am too worn out to do much more.