General Incoherence:
* Incoherently: This is the most direct adverb form of "incoherent."
* Ramblingly: This suggests a lack of structure or focus in speech or writing.
* Disjointedly: This emphasizes a lack of connection between ideas.
Specific Contexts:
* Confusedly: For incoherent speech or writing that suggests confusion.
* Unintelligibly: When something is hard to understand due to its incoherent nature.
* Erratically: For speech or writing that jumps around in a random or unpredictable manner.
* Jumbledly: When ideas are mixed up and disorganized.
The best choice will depend on the specific context of your writing.