The phrase "writes erratically" indicates that the writing style is random and inconsistent. Some synonyms for this term could be "scribbles haphazardly," "composes unevenly," "pens unpredictably," "drafts incoherently," or "formulates chaotically." These expressions offer various alternatives to help describe a writer's inconsistent style. Additionally, other phrases like "produces sporadically," "constructs disorderly," or "creates in a disorganized manner" could also be used to further broaden the vocabulary for describing this kind of writing. Ultimately, whether in creative writing or professional settings, using appropriate synonyms can add depth and nuance to one's language.