Several years ago I took a weekend workshop with Harold Ross, a Pennsylvania photographer renown for his "painting with light." I highly recommend this workshop, but I also recommend just going to his blog and checking out what's there. His thoughts on composition, I thought, are especially interesting. They're focused on still life photography, his specialty, but they're also relevant to other kinds of photography. Check it out here: https://haroldrossfineart.wordpress.com/my-thoughts-on-composition/
Gerry
This video on composition is brilliant. Thanks Gerry