Books about process-oriented writing:

Writing Down the Bones by Natalie Goldberg

Writing from the Senses by Laura Deutsch

The Power of Your Other Hand by Lucia Capacchione

Being an Autistic Writer by Jackie Schuld

Books about process-oriented visual art:

The Zen of Seeing: Seeing/Drawing as Meditation by Frederick Franck

The Practice of Contemplative Photography: Seeing the World with Fresh Eyes by Andy Karr and Michael Wood

Life, Paint and Passion by Michelle Cassou and Stewart Cubley