Creating Actions for Google Assistant requires a breadth of design expertise ranging from voice user interface design, interaction design, visual design, motion design, and UX writing that we've refined into a single discipline: conversation design.
By following our conversation design principles, you'll adapt to the communication system users learned first and know best. The more an interface leverages human conversation, the less users have to be taught how to use it.
Where you start and what you focus on depends on what you already know and where you are in your Action's development process. So, start at the beginning on our Conversation design site or check out the following more specific topics.